There's a bug when you use a negative integer in /env level.
/env jonty800 level -1:
Error blah blah.
[FIXED] Bug in /env level: Overflow Exception
[FIXED] Bug in /env level: Overflow Exception
You cannot use certain BBCodes: [img].
Re: Bug in /env level: Overflow Exception
Fixed... long time ago, can't be arsed to look up when.