I was testing the progressive bosses mod, more precisely the wither, killing it like 2 times and the third time the game crashed, when I try to rejoin it it crashes again, this is what the registry threw me, indicating that the error comes from this mod .

Crash report: https://bytebin.lucko.me/Ac3LBkiUeA

Full Log: https://mclo.gs/euyiS4B