https://bugs.winehq.org/show_bug.cgi?id=39637
--- Comment #4 from Dmitry Timoshkov dmitry@baikal.ru --- (In reply to Dmitry Timoshkov from comment #3)
Created attachment 52856 [details] Add CS_GLOBALCLASS to "Button" user32 class
The problem is that "MFCButton" window class is based on "Button" user32 class, and the application does GetClassInfo("Button") first and uses returned data as a template, including the class style. Currenly user32 control's classes are missing the CS_GLOBALCLASS bit. Adding CS_GLOBALCLASS to "Button" user32 class makes the application start.
There are already the tests showing that GetClassInfo() for user32 classes should not set CS_GLOBALCLASS bit. But the application wraps GetClassInfo() call by ActivateActCtx()/DeactivateActCtx(), probably that makes it behave differently.