Situation:

• Rotation mode
• One plain touches the renderwindow menue

How to make the bug:
Right click on the plain and keep button pressed --> Go with pressed button to renderwindow menue --> menue opens instantly --> select new mode

Now the attached rotation symbol by the mouse stays wherever you move. If you want to remove it, you have to go back to rotation mode, select a plain, press and release the mouse as normal and it goes.