Handy Toolset
Blender Crushed while I am running Boolean Modal. now I can not open the pie menu, what's wrong?
The top bar color is chosen as a visual switch to indicate if the modal operator is running or not. in case of blender crushing, its color is not restored, so the code thinks the operator is still running.
to fix it, open "Python Console" and paste the following code and press enter, it will restore top bar to default color and resolve the issue.
bpy.context.preferences.themes[0].topbar.space.header = (0.1373,0.1373,0.1373,1)