Hi,
As far as I'm concerned, ATL throws an assertion error, which seems to indicate that registration wasn't successful. I suggest you could try to use RegisterClassExA function.
1,You could try to use DECLARE_WND_CLASS and RegisterClassEx API to register class by name and custom control reference in dialog template to instantiate control through class name.
2,You should implement window class.Inheriting from CWindowImpl, and create control manually, duing OnCreate/OnInitDialog.
For more details about registering an ATL window class, I suggest you could refer to the link: https://stackoverflow.com/questions/575532/pre-registering-an-atl-window-class
Thank you!