>>You can't modify a class that's currently instantiated - you have to release all objects in memory that use that class before you can change the class.
>
>Hi Ed
>
>Ok but if i don't make a instant
>i only use the command {Modify class myClass of myClasslib.vcx}
>this is possible that foxpro make a instant to modify the class but don't release it when i close the modify form ???
>
>it's also happen when a class in the classlibrary(A) is a child of a other class in a other classlibrary(B). right after the modify command on the classlibrary(A) i can't delete the classlibrary of the parent(B) it also give me "FILE IS IN USE"
>
>I know that {Clear All} command release the possible reference to the classlibrary but it also cleared all memory variable. That's the problem.
>

The problem is probably that you have an object instantiated that reference a class in the classlib - you can't change the classlib while an object referencing something in the classlib is active. If you have a classlib Lib1.VCX, with a subclass of a textbox called txtSub1 and a ComboBox cboSub1 in it, and a second class library Lib2.VCX containing a textbox subclass txtSub2 whose parent class is txtSub1, you can't change any classes in either Lib1 or Lib2 if something based on txtSub2 is instantiated. You can't go back and change your parents...