Just added Origins: Classes to my server and when I try to join it gives the Invalid Player Data error and will not load me into the server. Removing the mod seems to fix this issue. My server is running the ATM 8 mod-pack plus Origins, Origins++, Prefab, and PMMO. Client-side log gives no info of the crash and server side simply states the issue is the Invalid Player Data. Server is run through Bisect Hosting and so far, it's the only real issue I have come across. The support side of Bisect Hosting states it's a world error that occurred. Any help would be appreciated.

I have the same issue, but in single-player only.

Still having this same issue even after many updates and months later.