The Minecraft Launcher is using an incorrect method of resolving domains by bypassing the preferred DNS resolver on Windows.
I suspect this to be an issue with outbound port 53 blocked on a router level in order to force an internal DNS service to be used. The router accepts port 53 and performs lookups on the router. This internal DNS on the router is capable of resolving external domains such as mojang.com. I simply don't want DNS Leaks which is why it's blocked externally. I may also mention, this is also the only program I have run into DNS resolving issues.
The Windows environment is specified below. This was performed on a clean install of Windows and using the "Minecraft.exe" alternative install found on https://www.minecraft.net/en-us/download/alternative/. This was launched from the directory C:\Users\Thomas\Downloads\mc\.
Launching on a Clean Installation
The Minecraft Launcher errors after a few seconds since launching the executable. Two error messages appear one after each other:
Couldn't load launcher core from C:\Users\Thomas\Downloads\mc\game\launcher.dll: LoadErrorNotPresent
Unable to start the Minecraft Runtime Environment. This is most likely caused by a corruption. Please try to reinstall Minecraft.
Screenshots provided.
Checking the launcher_log.txt file (attached), the error can be quickly traced:
[Error: 2020-08-21 00:11:10.4186235: NetQueue.cpp(471)] NetQueue: No ip address available. Error code 6, Host: launchermeta.mojang.com
[Info: 2020-08-21 00:11:10.4186812: NetQueue.cpp(506)] NetQueue: Action failed with result "Could not resolve: launchermeta.mojang.com (Timeout while contacting DNS servers)" (6) : https://launchermeta.mojang.com/v1/products/launcher/d03cf0cf95cce259fa9ea3ab54b65bd28bb0ae82/windows-x86.json
The domain launchermeta.mojang.com can be resolved within a second using my browser and even nslookup,
nslookup launchermeta.mojang.com
Server: UnKnown
Address: fd00::9:e803Non-authoritative answer:
Name: d1dulol58c5ch1.cloudfront.net
Address: 13.225.224.128
Aliases: launchermeta.mojang.com
Furthermore, the windows-x86.json on the same system's browser from the link mentioned in the log loads as expected with valid JSON. Clearly, this is an issue with the Minecraft Launcher resolving the launchermeta.mojang.com domain. Further investigation will show that the launcher fails to resolve any domain name.
A work around is using the host file to bind a domain name to its IP address. Previously, the host file was empty.
Launching with launchermeta.mojang.com in Host File
Since the previous nslookup resolved launchermeta.mojang.com as 13.225.224.128, this was then added to the hosts file:
13.225.224.128 launchermeta.mojang.com
Relaunching allowed the launchermeta.mojang.com to be resolved and as a result, windows-x86.json to be fetched. A new window appeared, but without any moving progress. This is screenshot Updating Minecraft Launcher No Progress where the progress bar remained at ~5%.
After cancelling the download, I then checked the launcher_log.txt and found that the file windows-x86.json did in fact download successfully,
[Info: 2020-08-21 00:37:38.6801885: NetQueue.cpp(603)] NetQueue: Starting net action https://launchermeta.mojang.com/v1/products/launcher/d03cf0cf95cce259fa9ea3ab54b65bd28bb0ae82/windows-x86.json
[Info: 2020-08-21 00:37:38.8277587: NetQueue.cpp(474)] NetQueue: Primary ip: 13.225.224.128, Host: launchermeta.mojang.com
[Info: 2020-08-21 00:37:38.8278007: NetQueue.cpp(541)] NetQueue: Action finished: https://launchermeta.mojang.com/v1/products/launcher/d03cf0cf95cce259fa9ea3ab54b65bd28bb0ae82/windows-x86.json
[Info: 2020-08-21 00:37:38.8278178: NetQueue.cpp(562)] NetQueue: Action finalized: https://launchermeta.mojang.com/v1/products/launcher/d03cf0cf95cce259fa9ea3ab54b65bd28bb0ae82/windows-x86.json
However, another domain still had issues being resolved,
[Error: 2020-08-21 00:38:39.0164035: NetQueue.cpp(471)] NetQueue: No ip address available. Error code 6, Host: launcher.mojang.com
The same thing was done as before, using nslookup to resolve launcher.mojang.com and then added that manually to the host file. I did this repeatedly until I was finally able to launch Minecraft.
Below are screenshots that mention issues that other people have run into and reported - which may be directly linked to this issue.
Launcher Authentication Failure
Even with the correct credentials, the message, "Sorry! Make sure you are online and try again" appears. The log mentions a failure to resolve authserver.mojang.com.
Check screenshot "Minecraft Launcher - Login Issue".
Launcher Fails to Download Files
After logging in and attempting to download the game, the download hangs halfway without continuing. This is a result of libraries.minecraft.net and resources.download.minecraft.net not being resolved within the launcher.
Check screenshot "Minecraft Launcher - Download Hangs".
Launcher Authenticating, Downloading, and Running Minecraft
After adding the previously mentioned domains to the host file; the launcher was able to authenticate my account credentials, download, and run Minecraft.
My host file ended up looking like,
13.225.224.128 launchermeta.mojang.com
143.204.147.134 launcher.mojang.com
99.84.115.68 authserver.mojang.com
13.249.39.84 libraries.minecraft.net
52.85.144.23 resources.download.minecraft.net
I should mention that anyone trying to use this as a fix may need to resolve the domains above with nslookup in the event that the IPs have changed for the domains.
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If you are saying I have some setup that prevents this individual application from resolving domains, that is not the case. Again, with Chrome, nslookup, and really any other software I've used, I have yet to run into an issue where resolving domains was a problem.
I proposed this because I've never seen anyone have such an issue, which leads me to believe it's not a problem on mojang's end. It could be a valid issue, but caused by something else, like ISP?
Sure, again - please read the entire issue. It's not an issue with my internet, ISP, DNS, etc. Since I can perform DNS searches with nslookup and any other software on the same system, it's not an issue with my computer.
And there are already issues regarding the messages found above with,
Couldn't load launcher core from ...
Sorry! Make sure you are online and try again
Logged in Minecraft Launcher claims No Connection while the system does have internet
Progress stopped mid-download during an update
I'm not sure if my issue is a duplicate of the issues presented above, but I do know this issue does cause those problems.
And a simple question, why does Chrome, Internet Explorer, nslookup, Outlook,, Uplay, (do I need to continue?) work as expected while the Minecraft Launcher does not?
Hi Thomas,
I just tried replicating this on my network and have been unable to.
For reference I blocked 53/TCP and 53/UDP on the LAN-IN on my router which is the same as blocking my devices from accessing any external DNS. I added an allow rule for only my internal DNS (53 TCP and UDP to 10.10.10.10) to ensure name resolution was still possible through to my internal DNS.
To test this had properly taken effect I tested using powershell and the following commands.
Resolve-DNSName google.com -Server 10.10.10.10 (succeeded)
Resolve-DNSName google.com -Server 1.1.1.1 (failed)
This indicates to me that the block is working as expected. A DNS resolution request to an external server failed, but against my internal server it works.
Loading up the Minecraft Launcher appears to work as expected following that configuration. I cleared my DNS cache to be sure and it logged on as expected. This indicates to me that your hypothesis that MCL uses its own DNS servers (rather than obeying the OS settings) is incorrect.
Without being able to reproduce this its hard not to assume its something to do with your home configuration.
Can you see anywhere my test is invalid? Are you able to provide test steps that would allow anyone to recreate your experience?
Ionic
Well that was a time waste, looks like the issue was an installation Proxifier which seemed to affect my HyperV instance when testing. With Proxifier v3 installed, it seemed to cause the problems mentioned above. There's a new beta of Proxifer and with that installed, those problems seemed to have gone away.
I'm still confused as to why this was an issue in the first place. I would like to see how DNS looksups are made within the launcher. Out of a couple hundred programs installed, this is the only one I've had networking issues with. But none the less, it seems to be an issue on Proxifier's end.
Thank you for taking the time though to recreate the environment IonicEcho.
Hi @unknown, thank you for your extensive bug report. I've actually had this in the back of my mind while going through many of the bug reports, and we've seen similar DNS lookup failures internally. I think you are on to something here - I'll take it up with the team!
We previously used c-ares for DNS lookups on macOS and Windows. We found it sometimes caused more issues than it solved, mainly that users could experience that they were not having connection through the launcher but had so on their OS.
Back in October last year we removed this and rely on the OS to make lookups. If you still experience issues, feel free to create a new bug. Cheers!
Hello @Ined, thank you for providing updates to this ticket. I'm glad to hear that and on my end, everything works as expected. Kind regards!
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Makes me think something is blocking DNS lookup on your end to the launcher, I'd say TS