It's OK. I know what cause this fatal error and I have fixed it.
In my APP class which is main Application class (Container) I have put Collection class (my developed Custom class) which I have used to put references of Form classes.
When I have delete that Collection class from Application class (Container) and put reference on that Collection class in new defined property in Application class Fatal Error didn't show anymore.
So, the solution is that I have must delete object of my class from container class and to create a new property to hold reference on that class.
Same thing, but Fatal Error happens in first and not in second case.



>Can you post code from your do() method? I'm not sure why do you've READ EVENTS in it because application needs only one READ EVENTS.
>
>>Can someone explain me this.
>>
>>I have PUBLIC variable oApp which is Application class and in oApp there is collection of forms oApp.Forms in which I add objects of my form classes.
>>In Application class there is method do() with READ EVENTS command.
>>Every time when I try to add form in collection oApp.Forms and to show() it VFP crashes and it brings on Fatal Error message with Exception Code = C00000005 indicating that there was an error in line in method do() where READ EVENTS command is.
>>This happens every second time.
>>
>>Can someone help me about this?