When the compiler detects that a variable is being set to a value outside of the range that variable can hold, it generates an error.
However, there are cases when this happens and the compiler only emits a warning. In most cases you are returning a value and passing a value to a function (i.e. a variable is set in an implicit way instead of explicit way.)
Check out your code to determine why the value is out of bounds or you will get a runtime error which is unlikely what you want your program to do.