Why does my Cyanogenmod themes crash everytime I want to apply a theme?

[AC Question]

I have an Oneplus one with cyanogen OS version 12.1.1 and android version 5.1.1, I wanted to change my theme and decided to install a few new themes, as soon as I installed them and click on the "apply" button my Phone loads for a second and goes back the the menu of the Phone itself. I can't change my theme because it keeps crashing, Anyone knows how I can fix this problem?

 

[Cyngn Ray]

What themes are you using specifically? Are you downloading them from the theme engine?