whenever I launch my server and a player joins it crashes

I dont know why its crashing but when I contacted the people who own the server hosting they said that it is a bug they cant fix and i will have to contact mojang, i have no datapacks and i think its the jar file crashing, even though i have the original jar file from minecraft.

 

here is the crash log

https://mcpaste.io/0e1e83ba2b2650d6