[My server keeps crashing due to me going through a new nether portal and idk why.]

After a couple hours and messing around a bit the server started working again idk what happend but its fixed.

[My server keeps crashing due to me going through a new nether portal and idk why.]

So i was in my suerver i made it in 1.19. i upgraded it and desided to go in the nether about 200 blocks away to see if i can get any new 1.20 stuff but as soon as i went through the new portal i just made the game kicked me and the server crashed i have tryed restarting my minecraft client my server and nothing works why is this i cant get back on my world.