If like me you suffer from a high degree of stupidity then might I share this warning with you. Today I managed to disable the capability to use either escape of F1 to launch the main menu. I spent a good hour investigating this problem, including copying over the scripts folder, creating a vanilla project, inspecting the main game loop file to see what I had done. It seemed the only way I could get escape to function was to insert a Debug() call.
Then I found out my error, there is a widget in the top left hand corner of the debug screen which allows you to keep it permanently on tap. I had in error pressed it. One of the features of selecting this option is that it apparently disables escape and F1. I am sure this is documented somewhere, but for those of us with fading memories who may not recall everything I have ever read , please take this post as a health warning