Crash Report: https://gist.github.com/CapNapu/7c0c245f08412d23a0189538a188e4c0

I think this is an Epic Fight bug; I do not see anything in the crash report that points to ModernFix.

The dragon was summoned, but that doesn't matter because the next time the server didn't crash after doing exactly the same thing.

When I join the server, I see that the console spams reports, but it doesn't crashes as such, so it lets me join.

Then, doing anything (literally) can cause the server to go into a "vegetative state" (since it logs me out and gives me an error, but the server is still on), and after a while it crashes for real.

This error only happens when the console spams reports, and that is rare to happen (hence the "Random" in the title).

Then, there is not much that can be done, Epic Fight stopped supporting 1.16.5 around a year ago. And they flatly refuse to patch any bug, (Even the critical ones) despite announcing the complete opposite on their Discord, but well, shenanigans...