[PrO.GameR]

Well as far as your code goes we can't figure out anything, it's not like its a missing bracket or sth.
but I'm guessing something is wrong with OnPlayerCommandText and the way it calls commands, did you by any chance hook it? because it might be a bad hook.
Check for your recent codes, anything player input related might have caused this (OnPlayerText, OnPlayerCommandText, OnPlayerCommandRecieved and etc.)

Edit: Yeah, I checked and it was for crashdetect's plugin
DL and use crashdetect if you don't have it already, and put these under one of your CMDs that doesn't function right.
PrintAmxBacktrace();
PrintNativeBacktrace();