Installing any APP hardboots phone and bootloops
For me it is the FaceBook app that causes the bootloop. I have CM11 on a Nexus 7. I used the Play store to update a few apps last week and when I came back to it, it was looping. I did several factory resets and found it was the latest FB app. I get an instant bootloop on installing. I just decided not to use it :)  Of course whatever the issue is (maybe some issue Android Studio is introducing that CM11 does not like) may affect other apps.