Win32 GetOpenFileName prevents app from exiting

I'm using Win32 with C++ to make an app that can load the contents of files through a dialog with the GetOpenFileName function. Everything works fine, except when I close the main window and the app quits and prints this to the console:

The thread 'Win32 Thread' (0xa50) has exited with code 0 (0x0).

But the main process keeps running and I have to kill it explicitly in Visual Studio of the task manager, and I get this output:

The program '[2620] DBSCAN.exe: Native' has exited with code -1073741510 (0xc000013a).

Does the GetOpenFileName create a new thread that I have to terminate myself ? I've checked out the msdn and a few tutorials, I don't seem to be doing anything different than the standard usage, open a file, read content, close file.

I can post some code if needed, any help would be welcome.

Thanks

try not setting an owner( ofnflags.hwndOwner = NULL ).

if you do set an owner, the occurring window will be threaded as a child window of the owner, which in turn would result in the behavior you are describing.