MT4 · Compilation errors
MT4 121 · The function is not of void type and the return operator must return a value | YI GOLD
Official meaning
The function is not of void type and the return operator must return a value
Possible causes · YI GOLD suggestions
Determine the cause from the official meaning, the triggering function and terminal logs.
Troubleshooting · YI GOLD suggestions
Locate the first reported line in MetaEditor. Check syntax, types, function signatures, includes and file permissions, then recompile.