Under certain circumstances on a Windows 10 (home) host, a Qt widget application appears to crash when a QMessageBox is invoked within an overridden "closeEvent" method.

The issue may be reproduced as follows:

• Create a new Qt widget application within Qt Creator, override the "closeEvent" method with code that instantiates a QMessageBox (e.g. QMessageBox::question).
• Compile application with either MSVC or mingw (64-bit) using debug or release settings. As I use Qt open source, this has only been tested with dynamic binding.
• Run program (either within Qt Creator or externally).
• Maximize window and close application by clicking the frame's close button along its rightmost extremity (forcing the cursor into the top-right corner of the screen is possibly the easiest way to reproduce this issue on a standard Windows 10 configuration).
• The application will subsequently crash whilst attempting to instantiate the QMessageBox (SIGSEGV Segmentation Fault).

NOTE: Whilst this issue sometimes manifests when closing non-maximised windows, it is far more difficult to reproduce consistently.

After further testing, this issue appears to be DPI related: it's only reproducible when resolution is set to 2560x1600, and scaling is set to 200% or 250%. issue is also reproducible under Ubuntu 20.04 (Cinnamon desktop) at resolution 2560x1600 with double (hidpi) scaling enabled.

The complete Qt project directory (zipped) has been attached for convenience.