vbplay handles
Though you don't think you are using handles, handles are passed all over
the place. They are given a different appearance in VB. When you load up
or open an animation a handle to that animation is generated. All further
references to that animation are via that handle. If that value gets
destroyed, or if you call a function out of the DLL while using a different
or invalid handle, this will generate this message.
I can't be more specific without seeing the actual code you are using.