https://paste.ee/p/Vwmgh
I was just getting some bedrock with other guys on PT and it suddenly started kicking me
it started happening right after i died, pressed respawn and while i was respawning server restarted

That's weird, I will look into it

Cannot reproduce

If it's a mod incompatibility, try and find out which mod it is

oh, it resolved itself? i think? and i didn't change anything from the last time.

Sorry for inconvenience.

https://paste.ee/p/NA04f
that happened again again, no idea why, while connecting to carpet 1.12.2 server

When it stopped happening, did you uninstall fabric API by any chance?

no

huh, it connected rn, after i stayed in 1.16.1 server for a while and tried again

oh, it might have happened after i canceled connection process

it might be not finishing all the registry manipulation and just getting stopped by minecraft itself so that the registry is in unfinished state and then on next connection it tries to overrite already existing thing?

That definitely sounds plausible.

I believe this is a duplicate of #91. Yes, I know that bug report is newer, but it is of higher quality so I'll keep that one and close this.

Well, the exception I was getting doesn't involve SinglePlayer and didn't get consistently fixed by restarting client, the only info I had was that long random error list I've sent (and the launch options), sorry for inconvenience.

It fits into the more general category of problems related to cancelling a connection to a server

It doesn't happen every time on stopping connection process( I think, will test when home) very basic fix I would think of is to force loading finishing or something like that, if it really only happens on aborted connection