3.6.5 Bugs and GUI Extensions
If you have installed any GUI Extensions (or used any software that may have installed them), make sure you see if
the problem exists with the extensions disabled and unloaded.
To do this, go to the GUI Extensions menu, and deselect 'Use Extensions'. Then exit and restart POV-Ray for
Windows. The GUI Extensions menu should then state 'No Extensions Loaded' (it may already do this if you've got none
installed). Then attempt to duplicate the problem again.