Qt main event loop in Win32 Dll

[MaxW]

I implemented a "win32" based library (COM Server) with "Qt" (5.3.0) support. Qt is used for some Core and GUI functionality, so the "qt main event loop" is much needed.

"QtWinMigrate" library does the work with "QMfcApp::pluginInstance" in my DllMain function. So far so good. My Dll can be loaded, by the 3rd party applications, and works well. In most cases. :-(

In one specific case it doesn't! The main event loop can't be started! I debuged the "QMfcApp::pluginInstance" method and discovered, that "SetWindowsHookExW" was successfull but the "QtFilterProc" is never called, so qt event loop is never triggered.

What can be the reason for this behavior? How can i fix it?

kind regards, Max