Solo press of Alt key hangs the app

[saxondigital]

If you press and release the 'Alt' key without pressing any other key the app will freeze. Pressing the key again, or clicking in the window with the mouse will un-freeze the window. This is a known bug with windows (10 & 11), details here:

https://stackoverflow.com/questions/11623085/pressing-alt-hangs-the-application

A fix would require changing the event handling of the freeglut library.