Servers not loading / Connection Reset Error in 1.17 (Caused by Firewall/AV)

Hey there! Does this describe your issue with the server list? MC-125762
The part with your Realms issue is invalid as this is a Minecraft: Java Edition Bug Tracker. See a helper's comment on that topic. REALMS-8185

Hey Martin! No, that doesn't seem to be quite the same issue. Mine happens ONLY in 1.17 and also is never followed by "can't connect to server" (As you can see in my screenshot, the whole server list is pinging and they just never load properly). They also mention that their issue only happens occasionally whereas mine happens every time I load up Minecraft in 1.17

I only mentioned realms to point out that this seems to be an online play issue in general, I don't really care about realms specifically.

Make sure your client operates on Java 16. You can use this tutorial for additional help with updating Java.

This is most likely a technical support issue. Take a look at your firewall settings, something might block your connection. For further assistance please contact the Community Support.

The server side has been a common issue affecting only 1.17. No definite fix/workaround yet, but some things to try:

1. Make sure the new OpenJDK16 is allowed through the Windows Firewall.

   1. Press the Windows Key and type "firewall."

   2. Click on "Allow an app through Windows Firewall."

   3. In the new window, press "O" on your keyboard and look for "OpenJDK Platform Binary."

   4. If you find it, make sure both the checkbox on the left, as well as both checkboxes on the right, are checked. Then click OK and try Minecraft again.

   5. If you do not find that entry, click Change Settings, then click Allow another app...

   6. Click Browse, then navigate to:

      C:\Program Files (x86)\Minecraft\runtime\java-runtime-alpha\windows-x64\java-runtime-alpha\bin\javaw.exe

      and click Open, then Add.

   7. Click OK and try Minecraft again.

2. Try disabling all VPNs, Hamachi, Antiviruses, and firewalls (especially third-party firewalls)

3. Try on another connection, such as mobile data via wireless hotspot or USB tethering.

4. Try creating a new profile in the launcher (Installations -> New), setting it to 1.17 (not latest release), and trying that new profile.

5. Try the following on Windows:

   1. Press the Windows Key, then type cmd.

   2. Under 'Command Prompt,' click Run as administrator

   3. Type netsh winsock reset and press Enter.

   4. Type netsh int ip reset and press Enter.

   5. Type ipconfig /release and press Enter.

   6. Type ipconfig /renew and press Enter.

   7. Type ipconfig /flushdns and press Enter.

6. Come to Community Support linked below to see if there are any other known workarounds.

Thank you for your report!
However, this issue is Invalid.

This is a technical support issue; this site is for bug reports only. We do not have the resources to provide you with technical support.
Please contact Community Support for assistance and refer to this ticket (e.g. "I have reported this issue on Mojira as MC-XYZ.").

Quick Links:
📓 Bug Tracker Guidelines – 💬 Community Support – 📧 Mojang Support
📓 Project Summary – ✍️ Feedback and Suggestions – 📖 Game Wiki

This might not strictly be a technical support issue. We've seen many cases in MCCS where it only affects 1.17, happens across most/all servers, and standard troubleshooting often does not resolve/pinpoint the issue. This also often affects connecting to servers like Hypixel as well.

This didn't helped us.

All this didn't worked for me

Didn't work for me either. This issue has to be a bug.

REALMS-8436

None of this fixed the issue for me either. I even reached out to my server hosting provider and we decided to try transferring the server to a different node. The issue persists. I tried flushing my dns...didnt work.

Community support is unable to help, lots of people are having this issue and nobody in the chat is aware of a fix,

 I contacted community support about this issue, but community support did not take me up on it. It is marked as resolved, but is this issue no longer recognized as a problem?

I've tried every solution for this in this thread and nothing has worked 😞

My friend is still getting this issue despite having gone through the fix. They pop onto the server for like a second before they lose connection and get the error"exception: java.net.SocketException: Connection reset".

me and my friend cant play on realms because this issue pops up, feels like we have tried everything at this point

@unknown, approach Community Support for further assistance. 😃

I tryed the same steps and it didnt work at all 😞

@unknown, approach Community Support for further assistance.

If you try the 5 items in the Mod Note and it still does not resolve the issue, then please go to Community Support for further help. There isn't a definitely known solution yet, and this error seems to be a catch-all error that encompasses many different causes and connection-related problems, but sometimes certain workarounds will work, which Community Support can help with.

this didnt work

@unknown, approach Community Support for further assistance. 😃

i tried this still not working

same tried this whole thing and just get told to go to community support and get the same "help" there best thing we can do is just not buy realm servers and stop giving them money

I have also tried every solution listed here and have not gotten a direct response from the community support discord after asking about it a couple of days ago. This appears to be an issue that is not resolved for many people. Hopefully this Internal Exception: java.net.SocketException: Connection Reset Error will get looked over soon.

This error has really broken my brain. I found this page and followed every step which got me no where. Then I went to the Community Support Discord server, which linked back to this page. Then I looked for other places where this bug was reported, all of which led back here. My laptop and my roommate's laptop both create the same error, but my other roommate's laptop does not. I don't know what is different about our laptops, and have no clue what is causing this error.

I tried the solutions above multiple times and still hasn't fixed the issue. Pls find a working solution

I tried this already, like a year ago.  Still not working.

Yea, like almost every comment here, i have tried everything listed in the solution, none of it has worked.

It even temporarily bricked my internet

I've been getting the same issue for the last 5 days. I've done everything listed above and I WAS able to log on for about 30minutes with no issue. I log back online after being offline for about 2-3 hours, and 10 minutes later, I disconnect AGAIN. 3 times with the same error as before.

This is really annoying and it seems like there is no actual solution to this. Realms is not working for a bunch of us, and no solution seems to be made.

Regular servers work absolutely perfect, realms does not. It sucks and I really hope a solution is made.

I sought to prove my issue was not a technical support issue but ended up proving the opposite. I reset my computer to defaults and reinstalled windows, cleared all apps and app  data and started from scratch. I can now access realms with no issues. This means I have no idea what the underlying issue is but if you’re like me and only really use your computer for playing Minecraft with your friends this is fixable.

issue has popped up for me too. this has to be fixed soon its just annoying. just payed for another month on realms too

I pay for my realm, this shouldn't be happening all of a sudden with no warning. I have not downloaded ANYTHING that would interfere in any way. I have update Java, I have done ALL OF THE ABOVE, but nothing is working. This is NOT on my end, there's no way that it could be since I haven't done anything different since two days ago when this started happening. This better be resolved soon. 

I had this issue for the past couple of days. I have now discovered that this is a purely internet-related issue. I had tried every fix I saw and nothing worked, however, every week I switch from my parents' house to my boyfriend's house. I had the issue at my parents' house but when I set up my PC at my boyfriend's, my Minecraft magically works again. I don't know if this is useful at all but I figured I should share nonetheless. 

This is still an issue for my friend, she bought realms so we could play on it but she keeps getting the same issue and getting disconnected again and again.

We have been struggling with this issue for over a week now and none of the fixes have worked. Mojang rly has to fix this shit

@unknown, please approach Community Support for further assistance. 😃

Tried everything here too, nothing works for me and it's only on one realm, not any other multiplayer servers.

I am having this same issue and tried everything listed with no success, I have just started my first realm and at this point in time I will be canceling my subscription.

None of this has resolved this issue for a player on my Realm. Up until the latest update, she was able to join and play just fine. After the 1.17.1 drop, she's constantly kicked from my Realm. It can be just seconds after joining, or 5 minutes after joining, but she cannot stay connected and gets the "Internal Exception: java.net.SocketException: Connection Reset".

We have tried everything listed above, and other solutions we've found elsewhere. Nothing seems to resolve. We thought we had it fixed when I purged her user data from the Realm, but after about 10 minutes or so she was booted again. Short of creating a whole new Minecraft account (which I must note isn't free to do) we've run out of ideas.

This seems to happen to ALL Realms she tries to join. Other multiplayer Minecraft servers she has no issue with. Which makes me think it's a Realms-specific problem, not an internet connection problem. Don't make us wait for 1.18 to drop to fix this issue!!

This is obviously NOT resolved - please stop lumping this in as being the same Firewall issue, because it is not!

Edit: There are other players on this Realm that can connect and play without any issues. Only this ONE player seems to be affected.

Same thing is happening to me, I just got the game and I haven't gotten to fully play it. I have tried every "solution" I could find. I have also already emailed for help and the solutions that were given didn't work. Then I was sent to the discord server and that was no help, no one even responded. Please fix cuz the issue is 100% not fixed.

I'm having all of the same issues as everyone else here, have tried all of these solutions and none have worked, the most time I can get into my realm for is 5 minutes at most, the rest of the time I can't even join, it's especially annoying because on top of it only being on one realm and not any multiplayer servers the realm is my realm, so I can't even play on my own realm while everyone else can, I just want to be able to play on my realm 😞. I emailed mojang about the issue and they referred me here and told me to upvote it so please get around to fixing this issue since it seems like a lot of realm owners are having it!! please don't make us wait till 1.18 for this issue to be solved. 

I am still getting this issue on a realms I own. The all of the above did not work. Please give us another work around so I can use the service I am paying for please!

THIS IS NOT A FIREWALL ISHUE it is a router issue its not just about the accounts computer its the whole network i tried to play the servers on different accounts and different computers but any device playing java will not connect to servers if they are connected to the same internet they wont work i am trying to figure out why it seems that the bug is cuased by some interaction that Minecrafts server backend has with an invisable part of your router wich causes them to disagree forcing you off the servers

ok this is weird this is a real bug but its not a traditional one its a bug that changes the way most personal server backends affect communications with your router its not that a firewall is blocking server entry its a bug that is related to a communication between most Minecraft server backends and the router and providers backend I get a bad feeling that no one can fix this as it is entirely out of Mojang's control if it is what i think it is than it can't be fixed as it has nothing to do with values you or Mojang can modify if you get this bug and any of those "fixes" work cool however if your like most of us its too late as i remember i did get this bug one more time before this and the only thing that happened to fix it was once my parents bought a new router so yes there is a bug but they laterally cant fix it as its not as simple as changeing the game as the bug is at the router level and i get the feeling why pubs work is because there is a plugin fixing the bug on larger servers that smaller servers cant access which is why realms is having the problem too as realms don't use any plugins

This bug is still present in 1.18 so I tried to create a ticket for it but was told it's a duplicate of this issue, even though this ticket specifically mentions 1.17. Either way, I am completely unable to connect to my Realm and keep getting this error over and over. I have done all the steps outlined in the Mod note, to no avail. Please reopen this issue, thank you.

Hey Mojang! Great to hear that you think you've fixed this! I'm terribly sorry to burst your bubble, but you haven't 🙂. This bug continues to affect many users (All of whom pay for this game, and many whom pay you for the realms they try to play on!) in 1.18! It would be wonderful if you could fix this, or, if you can't do that at the moment, reopen this issue - as, incase you haven't noticed - this still happens!

yeah i am also currently having issues with this error message and did everything on the list including resting my router and still no luck

I am also still having this bug in 1.18 Bought a realm today and for some reason everyone else can play on it except for me, the realm owner. Would appreciate this being re looked into. None of the steps above fixed it for me.

I too am running a vanilla server. 1.17 was fine, updated to 1.18 today and now all three of us are seeing the same error. On three different laptops when trying to connect. This is not fixed, at least admit it's not, follow up with your users with a quick message and we're good.

Im on 1.18 and this problem is still occuring for me and I have not found a fix yet, and cannot play on my realm but my brother on the same router and wifi can. 

I was about to try step 6 when i came to the realisation that I don't have a minecraft folder in program files x86 or the just the other program files.

This shouldn't be an issue right?

I have bought realms again yesterday after a long time only to be met with this issue in 1.18, same as years before. none of the solutions in this post work, and neither do other solutions that show up on google. Please fix this and change the status to UNRESOLVED as i feel pretty riduculed and insulted as a paying costumer.

I bought a realm to play 1.18 with my friends. They could all play, but I kept receiving this error. I can join other servers fine, and none of the solutions above helped my realms issue. 

I contacted support, and was told it's a connectivity issue on my end, so why am I able to join the realn perfectly fine with a different account, on the same PC, router, and installation? 

This is still an issue reopen it.......

Still an issue, I think... I could be wrong but this is still happening in 1.18. I've tried everything, including deleting everything MC related on my PC and then reinstalling MC.

This bug is very much NOT resolved. I sent a help request to Mojang and got this as a response:

"We are sending a follow up regarding the status of your case: this ticket is still being investigated and we do not have further information on this issue yet.

As a quick reminder, please do not submit additional tickets about this issue during your wait time. If you do have more information or questions regarding the case, please let us know by replying to this email. 

Going forward, we will reach out to let you know if the status has changed or if it is still being investigated. Thank you for your patience while we look further into this matter."

I tried basically everything listed here and on the internet to try to fix this and nothing worked. It's only not working with me, the owner, while my friends can join just fine. Other servers I can join just fine, so it's a Realms issue. I've used realms for previous updates in the past just fine and had little to no issue with it, and I literally can't even play it at all now. 

Every time I try to join a multiplayer server, I end up falling into an abyss of nothing. Shortly after, I get this error code. I cannot enjoy the time I'm supposed to enjoy with my friends and I'm starting to get upset. They can play, but for some reason, I can't.

Having the same issues, really hope this gets fixed soon. Notably it seems to almost always kick me while using a portal or a boat.

Just another comment in an attempt to get this reopened

Update: still not resolved!

A friend of mine has been able to join my Realms server since the 1.17.2 drop. We have already tried all of the trouble shooting tips mentioned here and elsewhere, short of "try another internet connection" because she does not have access to one. (Her computer doesn't have wifi capability, so her only option is direct wire.) She was able to access my Realm prior to the 1.17.2 drop.

We had hoped with the drop of 1.18 the issue would be resolved for her, but she still cannot join. Ten other people, located in various parts of the world, have no issues joining Realms. Only her. She can join ANY OTHER Minecraft server without issue. Which really seems to point to it being an issue with Realms coding and the internet connection, not only the internet connection alone.

Tell me, why should I pay Mojang/Microsoft money for THEIR private server service when I could throw my money at another service and actually get to play with ALL my friends? This is an option I'm seriously considering at this point.

Note: When the 1.18 drop happened, we started a new world in Realms. She was able to join at first, move around, pick up things and put them down, no problem. But as soon as she went through a Nether Portal she was immediately kicked, and after that every time she logged on she'd be kicked almost immediately.

I tried running a command to teleport her to different coordinates, in case she was stuck in limbo between Nether and the over world and some sort of internet bug was causing the error when loading between worlds. It stopped the immediate kicks for a little while and she was able to move about in the over world again, but after a few minutes they started happening again (still in the over world) and the tp trick didn't work any more.

Wooo yeah, time for yet another comment reminding Mojang that this isn't fixed!

Yeah so, I refuse to continue to pay Microsoft monthly for something that doesn't perform well. Let's face it: they are not going to bother to fix this unless the amount of people pissed off and cancelling their subscriptions is greater than the amount of people who pay them each month for subpar service.

I have canceled my Realms subscription and signed up for Shockbyte hosting - same cost, more RAM, easy to import saved worlds, so many extra things I can do with their support that I could not do with Realms AND my friend can now log in and play with us without being kicked every 5 seconds to 5 minutes. We've had 3 whole days of fun together without a single frustrating moment. Added bonus: less lag, faster loading, better user management, and stellar customer support. All things Realms sorely lacked.

Yeah, this is never gonna get fixed. They said to me that they were gonna fix this half a year ago and here we are, still not fixed. I feel like mojang doesnt really care about things if they dont lose enough money on it. I have seen youtube tutorials on this bug older than 4 years so clearly they dont care. Im really mad cuz I REALLY wanna play the new update with my friends on their realms, and on my own realm. I own a world that is 2 years old and weve had 12 different people on it to build amazing things and go on fun adventures. But I cant do that anymore, so my love for minecraft has really faded away. Great job mojang. 

I also want my money spent on the realm that I cant use back, thanks.

It is unfortunate Mojang didn't provide further solutions for this issue. Though I haven't tried these myself, below is a compiled list of solutions that was stated "worked" by users posted on Minecraft forums (Reddit, MCForum, Discord, etc). Here is the list:

1. In Windows Defender Firewall with Advanced Security, ensure that in all inbound "OpenJDK Platform Binary" rules, under the "Advanced" tab in the Properties window, "Private", "Public" and "Domain" are ticked (sometimes having "Private" ticked only also solves the issue). Additionally, change all "blocked" rules of that list to "allowed".

2. Stop using JDK binaries provided by the official Minecraft Launcher. The recommended JDK is either Adoptium or AdoptOpenJDK. Download the one that suits the required Java version for the Minecraft version. The downside of this method is you have to set Java binaries for each individual installation, which can be found under <Java installation path>\bin\javaw.exe.

3. Many users have faced this issue because of router config problems (that may conflict with Minecraft Multiplayer itself). Either replace your router, cable, factory reset the router to mitigate this issue, or you can use a DNS over HTTPS client like 1.1.1.1 or a VPN like ProtonVPN to skip through all the complicated stuff.

4. Whitelist your Java installation folder and/or binary in your antivirus or Windows Defender.

5. Use java.exe instead of javaw.exe (remember that any JDK can use this method). javaw.exe is the non-console Java binary. A command prompt window (or terminal in other OSes) will appear when you use this method. Don't close that window unless you want to close the game.

6. Maintain a low render distance value (or low graphics settings). Sometimes this can improve your connection reset problems.

7. Flush the DNS using the steps given by the moderators above. This method is not guaranteed always to work, but it was reported to work temporarily.

8. If you are using a network card for network connection, switching to the motherboard may help mitigate the issue.

9. If you are using a NAT-VPN application like Hamachi to allow your friend to play via "Open to LAN" in single-player worlds without having to be on the same network, completely uninstall it immediately. It can interfere with the network and cause network problems.

10. Make Windows prefer to use IPv4 instead of IPv6.

11. Uninstall all resource packs and disallow servers to download and automatically load them too.

12. Make your computer's IP static and set up the correct port favored by Java Edition.

13. The new launcher from the Microsoft Store is such garbage because it breaks things. Uninstall it and download the launcher for Windows 7/8 on Mojang's website (also works on Windows 10).

I won't be responsible for any errors or losses you have if you follow the above methods. Consider them provided "as-is". You should consult an expert if you don't know what you're doing.

i've tried every single method listed above and this still isn't working! i can't belive mojang didn't fix this issue between 1.17 and 1.18; unless there's a different solution or an update that patches this, i have no reason to renew my realm in 3 days, not that it's much of a loss for them.

Getting this error. the interesting thing is if I connect via the old launcher I don't have this problem. If I connect on my old computer that can barely run minecraft I don't have this problem. if I use Proton VPN I don't have this problem. I have all my firewalls turned completely off.

I've tried all these fixes and it's definitely not fixed.

Can't believe this is still a thing. I have tried both realms and 3rd party hosting but both give my brother this error. None of these "solutions" work. Please re-open this thread!

Wrote another report: Thread "Servers not loading / Connection Reset Error in 1.17 (Caused by Firewall/AV)" needs to be re-opened! The solution doesn't work

And got this back: Please follow the instructions in the original report MC-227913 and ask at Community Support.

Sorry but this system is a joke. Hope that they lose many Realms customers because of this.

I only have this problem on my new pc. Works on the old one and on my dad's pc. This problem seems to only occur with a specific combo between account and pc. Tried to log in to another mc account on this pc and it works fine. Tho it's my friend's account so I can't play on it. I WILL NOT buy a new account! Please just fix this problem already! You have not given any updates if you're working on this bug or not and that's really bad communication right there.
But there is this thing that we all prolly know, and that's that Mojang will prolly not fix this because they aren't losing money on it.

This still isn't fixed and I can't play on a Realm my friend bought for us. Please look into this and re-open the thread. 

I emailed the help provided on the minecraft main page and the information they gave me is the same as it is on here and didn't help at all, the issue is still happening so please re-open the thread. I bought the realm only 2 days ago and I can't even play on it. 

I'm having a problem where I get the error "Internal Exception: java.net.SocketException: Connection Reset" when I try to play on ANY realm. I can play fine on multiplayer servers such as hypixel without getting the error/booted.

I also didn't get the error on realms when I tried out playing with a VPN, hope this gets resolved soon.

I have also tried all the suggested fixes. 

I'm a server owner and my players encountered the same problem. Disabling the Whitelist made the issue "better". Players, instead of instant disconnecting, now are able to play with massive delays (talking about seconds of conceivable delay here), which to be clear, was not present normally. Could any other server owners confirm my findings by temporarily disabling their whitelists? (Please be careful and remember to re-enable the whitelist after testing) Or could any server owners without a whitelist disprove my guess?

I find it laughable they still have this marked as resolved when it clearly is not.

As I no longer have a Realm subscription, I am unable to test your theory, but you may be on to something. We had tried completely deleting my friend's user information from my server (by downloading the file and then editing user files and then uploading the new files) but that gave us all of 10 minutes of playtime before she was back to being constantly kicked.

I wouldn't know how to go about disabling the whitelist of a Realms world, though. I assume it's another matter of having to download the entire world, manually edit files, and then upload?

The massive delays are an obnoxious side effect, but if users are no longer being kicked then it definitely uploads my belief that this is definitely a Realms server-side issue and nothing to do with anything on the user end.

Well after a year of sending gmail back and forward with mojang they finally said that the problem is on our end and that there is nothing mojang can do to fix this. I also got to hear that I could have done a refund on my realm whilst my subscription was still up. Which is strange because they told me a year ago, ONE WEEK after I bought the realm and contected them, they told me I couldnt make a refund. Instead, they gave me another month for free but that didnt help due to the fact that I still had this issue and no fix. 

Also want to add that this behavior is a little scummy in my opinion. Just because its a small part of the community that has this problem, they wont put resources to actually try to help us. They simply do not care about this problem nor us because they arent losing enough money on it. This is also why it says "resolved" when its clearly not. They do not care about this problem at all. What we need to do is just to try all the things we could think of and try to help eachother. There are plenty of tutorials on youtube that could potentailly fix this issue for some. 

It seems this issue only happens on Windows, and mostly happens when the computer has ever had Hamachi installed on it at some point, even if it was removed later on.

Please try the following and let me know if it works:

1. Press the Windows Key, then type {+}cmd{+}, right click on "Command Prompt," and click *Run as Adminstrator*.

2. Type netsh interface tcp show global and press Enter.

3. If Receive-Side Scaling State is disabled, type netsh interface tcp set global rss=enabled and press enter.

4. If "Receive Window Auto-Tuning Level" is disabled, type netsh interface tcp set global autotuninglevel=normal and press enter.

5. Restart Minecraft and try the realm/server again.

@David Wang, I can confirm your fix worked.

The first one in a dozen threads, bug reports and more. It's interesting that the culprit is Hamachi leftovers, but I can't say I'm terribly surprised given the significant amount of network settings it reconfigures. Thank you so much for taking the time to find and resolve this issue for those of us who have been searching for the solution for years in some cases.

@David Wang

This solution was also successful for me, thank you for taking time to write this out! +1

You are welcome. I did not find the fix, but just passing it on. Glad it worked for you.

None of these solutions work for me as of 1.19.3. I am unable to connect to any realms servers, but other third party servers will connect fine. Seriously hoping for some new solutions or fixes for this, because this problem is NOT solved for everyone.

Running into this issue on a server we're hosting after moving the VM to new hardware, never ran into this issue before. The network layout, IP addresses, and everything else are exactly the same. The VM was moved in its entirety, so all settings in the OS are identical.

 I have this same problem, exception is that I can connect to this other server and play on it just fine. I have no idea why. I use mobile hotspot via my phone. Used to work fine, playing minecraft, with no issues until recent update. 

An employee at the Minecraft support told me, to write a comment here:

I am having this problem ("Internal Exception: java.net.SocketException: Connection reset") on version 1.19 and tried everything in this thread.
I even made a clean installation of Windows 11 and tried different networks (cellular and a different home network). The server was also moved to different hardware.
And all I did was not playing for 4 months. The server configuration was not changed in this time.

I updated my computer and Java.

I tried allowing OpenJDK16 through the Windows firewall but : 
I couldn't find "OpenJDK Platform binary" but  I found javaw.exe
The private checkbox wasnt checked so I checked it. But sadly it didnt fix the error.
I dont use vpns. Never installed hamachi. Only have windows defender as my antivirus.
I also tried while deactivating my private and public firewalls.

I tried with a new profile on latest release. 

I also tried following these steps : 
Try the following on Windows:
Press the Windows Key, then type cmd.
Under 'Command Prompt,' click Run as administrator
Type netsh winsock reset and press Enter.
Type netsh int ip reset and press Enter.
Type ipconfig /release and press Enter.
Type ipconfig /renew and press Enter.
Type ipconfig /flushdns and press Enter.

And these ones : 
Press the Windows Key, then type cmd, right click on "Command Prompt," and click Run as Adminstrator.
Type netsh interface tcp show global and press Enter.
If Receive-Side Scaling State is disabled, type netsh interface tcp set global rss=enabled and press enter.
If "Receive Window Auto-Tuning Level" is disabled, type netsh interface tcp set global autotuninglevel=normal and press enter.
Restart Minecraft and try the realm/server again.

I never had this issue with my old computer and this one is new. 

This issue is not resolved. I tried everything here and it didn't work.

I have this same issue. none of the above fixes it. i only have this issue on my account when trying to play on Realms. java multiplayer to a old school private server works fine. same PC, loads my son's account into Realms just fine. My account on his PC, i still instant disconnected. just to further prove its not on my side, i tried a different NIC, different cat5E, different router, different modem, different ISP, moved states. It seems to be an issue with my account, but the terrible tech support closed my ticket saying i have to type crap on this because according them this is clearly a bug on my side. 

Can we bump this? I did many of the same steps as OP but agree that it seems to be an account issue. I had a LOT of entities loaded for a very long time and this begins my theory. I think having the entities loaded must have kicked me / caused an error on the realm instance/server which SEEMS to have resulted in my account being blacklisted from joining realms servers. My brother’s account works fine on my computer and network.