[maij]

i havent red your code, but to me your problem sounds excisting of a out of array variable, or using a function with an invalid variable;

if you have any loops, check the size of the variable used , which should be an array, is big enough for the loop

note that return 0; ISNT required for getting this message, also for failing codes;
so for example in a out of array loop, it will return 0; automaticly