[wups]

If i remember correctly, char arrays hold up values from 0 to 128. Then again, textdraws can have ID's up to 2048.
So,

pawn Код:

Text: uMsgBox_Content   [ MAX_PLAYERS char ];

Shouldn't be a char array.
And you didn't mention anything about the box size. Ex. does the text move to the next line by it self, or do you have to use ~n~?