make sure you always have at the start of your projects

if you're including other files, they sometimes point to the wrong file / function

and make sure you're running the right script,
OPTIONS->PREFERENCES will show you which script you're actually running, the toolbar run buttons
Play current script <- use this for the script you're editting
Test Run <- use this for the one set in preferences
Debug Run <-as above

hopefully one of these will fix it