i was opening systemsettings, chose workspace design and the default look and feel screen just stays black when resizing the window or chosing another option on the left panel, it crashes.
could not reproduce the crash, but the black window thing remains.

Reproducible: Always

Steps to Reproduce:
1. open system settings
2. chose workspace design
3. see the problem

Actual Results:  
i was opening systemsettings, chose workspace design and the default look and feel screen just stays black when resizing the window or chosing another option on the left panel, it crashes.
could not reproduce the crash, but the black window thing remains.

Expected Results:  
should not crash and should show the contents.

http://s18.postimg.org/a460edqah/Bildschirmfoto1.png