Error 15 or Eve Stack overflow means that either the stack size is insufficient in your program (variables and such), a recursive function fails to exit, or multiple timers are firing simultaneously.
For insufficient stack size.
You can expand the stack size by manually inserting the code below for Workshop4 Designer/ViSi and ViSi-Genie Magic
#STACK 4094 //max stack size
Using Designer/ViSi add the line at the top of your code as constant.
Using ViSi-Genie Magic add the line using Magic Code in the Constant/Global/Data Insertion
For more information about the #STACK, you can check the 4DGL Programmers Reference Manual
For recursive functions.
Check iterations, recursions or function calls that may possibly cause this. You can add like, return or return 0 as an ending argument to make sure that it terminates.
It can also happen in conditionals (especially nested ones) where you think the program might not actually reach the argument; it would still be best to add an else clause with just the return statement in it just so the memory gets freed once it exits the function.
You can find this error on Internal Functions Reference Manual > Runtime Errors.
If you are still having trouble, you can contact our technical support, who will help you check your code.