Comment 1 for bug 783134

I believe the error below relates to this one

 unity-window-de[2149]: segfault at 318 ip 0000000000415d6f sp 00007fff2301ff90 error 6 in unity-window-decorator[400000+1b000]

This also happens on Katya, randomly.
The service "unity-window-decorator" can be restarted - and then the minimize-maximize-close buttons, and the upper window frame (in the proper way) are back and functional.