Actually, not quite true – I found this topic after some digging and it resolved it for me:
https://meta.discourse.org/t/user-badges-500-internal-server-error/22459/8
Pretty much, there should be a default group for every new badge created – if not, user’s badge page will crash if he has a badge that has no group. Since there was no warning or default, I didn’t think much of it about assigning it a group.
Similar to a .NET form where you have radio buttons - always have 1 checked by default or bad things happen.
So this is for a new badge you created?
Correct. Consolidating old topic:
I have a feeling it has to do with this – by resolving this issue below, I bet I resolved this one, too:
I granted a badge that had no badge group. Since there’s no default group for badges and no warning you HAVE to have one or it’ll crash a user’s badge (if assigned), this causes both the error in this thread and the one linked above.
I recommend adding a default group for all badges that just sort of hovers to prevent this (better than warning - people dont read warnings, ehehe)