"Not a sub or function name" error while using script library

Having troubles with "Not a sub or function name" error when trying to use your procedure even if you are sure that everything should be working?

I have recently suffered from another from many Lotus Notes errors. I created new sub in a script library and added library import in declaration section of action in which I wanted use my code.
But when I was trying to use my new procedure, LN was still showing the error.
Recompiling all scripts in database didn't help, google on my vile query also found nothing.

Long thing short, simply closing and reopening the form with action helped...