Hi SoyEli,
I presume that you have some code in that Sub.
Is it possible that you have conditions (if statements) that would prevent a value being returned for the Sub, that you are only returning a value when a certain condition is met?
You can paste the code and let everyone have a look.
And its probably stating the obvious, but it is only a warning. If your code is doing what you want it to, its probably safe to ignore it.