>There is indeed a difference in this regard.
>
>In form1 prg1 is called from the click() event of a button:
>form1.cmdrun.click()
>
>While in form2 it is called from a METHOD I added to the form itself called form2.fire()
>
>Do, you think this is why ?

Of course.
The button have not a error() code, then VFP use ON ERROR.
Add a messagebox() in Button.Error() and try.

If Form is not present in the call stack,
then the Form.Error() is not used in it's controls,