Crash server (ShreddedPaper)

Please fix this error https://mclo.gs/4bOnNkc
Core: https://github.com/MultiPaper/ShreddedPaper
Version 1.20.6

That's mostly caused by that unsupported fork, with Folia that likely wouldn't happen.
But set Nametag prefix to empty in config, that will disable scoreboard teams for pvpmanager and the error shouldn't happen anymore.
Or upgrade to premium version or free pvpmanager lite v4.0 (will reset config and messages)