Hi Michel,
Are you by any chance using this to enable/disable a menu option (in a SET SKIP OF)? (s)
ActiveForm will obviously fail if no form is active, so you have to specifically code for that instance by checking whether _SCREEN.ActiveForm is an object:
IF TYPE("_SCREEN.ActiveForm")="O" AND !ISNULL(_SCREEN.ActiveForm)
... do whatever here
ENDIF
This type of code is crucial if you have toolbar events that fire on forms that are expected to be open. My guess is that somewhere in your code a menu option is not disabled when there's no form active.
VFP 5.0 has a forms collection that makes this a little cleaner to deal with.
+++ Rick ---