Nether portal crashes the game when used

Have the same problem (and reported own bug since I did not find this, see REALMS-5121). Though I never get stuck in nether. Even if I have been in nether for quite some time before I go back (and it disconnects) it always roll backs to a old backup from the overworld right before I entered Nether when I reconnect. But this happens very, very frequently. I try not to enter the Nether for longer periods since all work will be lost. 

I also tried with more portals since I though it was related to only the one I had, but then it seems to happen more when added more portals. I removed those again to make it playable. In some cases it was 100% reproduce-able when I enabled and used certain portals.

Hi this issue is still happening in v.1.16.20.

It always happens in our realm whenever my friend exits the nether portal. Everyone gets disconnected, and when we log back in the realm has been rolled-back to the last back-up. We lost tons of progress. We are now avoiding the nether which sucks since it is the nether update.

This happened several times this evening. On my realm, the crash seems to be triggered by one particular friend. After the second time, he reset his Xbox One X and was able to go through the nether to his desired destination, but upon trying to return triggered the crash again. I was playing through Windows 10, a second friend was on an Xbox One S and a third friend was playing on a first generation Xbox One.

Is this related to REALM-6812? Is it the same issue or is this unrelated? The symptom in this issue is also part of that issue with REALM disconnects and rolls back to a older save. But this particular issue is only the case where the disconnection happens when traveling from Nether to overworld. For me the game crashes almost every time when using a portal.

@unknown If you are able to provide a copy of your realm along with the relevant portal coordinates that might help in diagnosing your specific issue since it predates REALMS-6812. You can upload the world to any common file-sharing site and provide a link to the upload.

Find the map at: https://www.dropbox.com/s/0d6j38v5z17vjbw/Realm%20copy.mcworld?dl=0

I was trying open/closing portals in the map to try and figure out when and why it crashed and when it did crash I downloaded the world. I made a copy of the downloaded world and did the exact same things again and it crashed again. However when trying it a few more times it did not crash every time. This is what I did:

1. Start the world in survival (might not effect things, but survival take longer to enter portals)
2. My player starts close to the portal
3. Go to small portal directly at coordinates: 476, 84, 60
4. Open portal using flint and steel and go trough it (there is a portal in Nether already which is can connect to)
5. In Nether enter other bigger portal just close by which is already opened at coordinates: 69, 67, 6 (this portal is already connected to a portal in overworld.
6. Game crashes when overworld is loading

If it does not crash it might be an idea to just enter the Nether, gathering material for some time, leaving Nether again using the bigger portal at 69, 67, 6 and it most often crashes. When leaving Nether using the smaller portal it quite often crashes some time later when moving towards the "base" where the larger portal is. It seems like the bigger portal is the one causing most crashes. There is also a third portal not enabled since I got the feeling it just caused even more crashes.

I hope this info can help.

@unknown Thanks for the test world - we haven't been able to repro the crash in the latest build we have, and hope that this is fixed for you on Realms now too. Could you confirm?

Just tried it again and doing the exact same procedure and it disconnects when entering the bigger portal. I was using the exact same world.

I've been suffering this issue intermittently since forever, probably about since the ticket was registered. What I can say for sure it is happens frequently (though not yet predictably) towards iPadOS Minecraft 1.17.10 when exiting the Nether.

Seemingly not with Windows Minecraft Bedrock players, regardless if the portal is in old or brand new chunks, precise or arbitrarily located portal pairs and I only build small portals. 

Considering the annoying rollbacks and the not insignificant Realms subscription fee, it's really harming the Bedrock vibe, please try to troubleshoot this?

Would testing it on a realm help to diagnose the bug at all? Any percent of the player-base consistently having server rollbacks seems to me to be too many...

I made a ticket with the same overall bug, the server shuts down after a period of time after opening a portal. It will shut down immediately if I enter the portal after making it back to my main base (then going back a portal at my main base). Think this has something to do with saving the world, but I defer to your assessment.

I do not have access to the realm world as I am a third party (friend's server). But could give someone from Mojang/etc access to test this issue live.

It is still an issue as of 1.19 

I can enter the nether just fine but as soon as I leave all mobs freeze and after a few seconds the realm crashes and rolls back 

Have the issue as well in our realm! Makes the game unplayable having progress randomly rewound. horribly depressing.

Bedrock has so many bugs that break the game..