Default [Q] has stopped?

So I've been running Graviton 2.0 on my Nexus 5 for a few months and recently I've tried upgrading to 2.6. Problem is, when I install the updated rom, I get the "Unfortunately, has stopped" error message loop times infinity. I tried installing 2.6 by booting into recovery mode and installing the zip using CWM. I then wiped the cache and the Dalvik. I've also tried doing a factory reset prior to the previously mentioned steps and that hasn't worked either. Any help would be much appreciated thank you.