Why does my MC server forge 1.16.5 crash?

I created a Minecraft server with my friend.

We played 2-3 days, one day I went to the Nether Farmte there to relax and then the server crashes

when I start the server my friends can play on it and can continue playing as always, but when I do it the server crashes

if I go on it alone Joine crashes too, so the problem lies with my Acc

if my friend logs on with my acc and logs in with the server, the server crashes again, so it has something to do with my mc acc

What hardware does the server have so CPU RAM and how many mods have you packed up to how much do you play?

Didn't look at every line now, but I did notice one of the few that I've seen.
Could it be that you are outside of a border? Because as far as I understand, your chunk can't be loaded.

Also I quickly looked at the text JZ, so either it is due to the blocks oo or you are outside the world so out of the border. You have to look at files, there's a player file somewhere that you can edit and somehow change coordinates.

For 3 we play

cpu i7 8700

I use ram 10gb for the server

approx 14 mods

Thanks, where can i find the file?

As we said, I just don't know.

Then I really have no idea why it crashes

The file is in the server folder