Ubuntu 15.10 - UI themes aren't correctly loaded

Question

I recently upgraded to Ubuntu 15.10, and now themes aren't being applied correctly to the UI. Fonts are rendered inconsistently, with elements appearing in what seems an old GTK default. My customized themes/icons/fonts are not loaded, so parts of the interface are rendered with the default Ubuntu theme (Ambiance) and other parts, with an ugly old-looking theme. The scaling factor configured for UI fonts is not applied.

I already tried creating new, empty user accounts, but the problem with the font rendering is still there. I even made a fresh installation of Ubuntu 15.10, but that didn't solve the issue, either.

I have noticed that sometimes the problem is solved by forcing Compiz to restart (and Nautilus for the desktop icons), executing these commands:

killall compiz
killall nautilus
nautilus -n &

I didn't find it easy to describe the problem, so maybe these screenshots that could clarify the explanation:

How my desktop looks now

How it is supposed to look

Answer 1

This problem was solved for me when I downgraded kernel. I installed on Ubuntu 15.10 with kernel 4.3 and the theme don't apply apply properly. When I downgraded to the stock kernel the theme worked properly.

Answer 2

I have faced the same problem in Ubuntu 15.10 when replaced the HDD with SSD. Fonts started looking just like in your pictures and I couldn't apply Numix theme! I solved this by disabling the Ubuntu user auto-login in a system. When I switch my laptop, I have to enter password to see desktop but fonts and themes are now looking correct.

Answer 3

I'm experiencing same problem since upgrading to 16.04 from 14.04. To load themes correctly, I had to restart unity by

$ unity

I searched and thought it could be a graphic driver problem. So I installed nvidia-361 and nvidia-prime(I'm using Optimus laptop), the problem resolved. But only NVIDIA mode. On Intel graphics, the problem remains. If you are not using Optimus laptop, try installing proprietary drivers.