[Mina]

number of arguments does not match definition :
Function(int a, int b, int c){
return a+b+c;
}

Seems you used Function(1, 2) or you used Function(1, 2, 3, 4);, but you must use Function(1, 2, 3);


And function "OnPlayerCommandText" should return a value:

In the last line which is a }
Before it write return 0/1;