I am using Stock Android 4.2.2 on Nexus 7 2012 Tablet. I rooted my tablet using the Motochopper Root. I was able to download OTA 4.3 Update using normal procedure on my tablet however, when I tried installing the update, it just stuck at the android guy with error at startup. I tried downloading the OTA update again as it just disappeared, however it is stuck at waiting to download. I tried Nexus Tool Kit downloaded Stock 4.3 OTA and tried to install it using ADB sideload command. However it gave an error and mentioned some error file and exited. Please Help me out . I also tried full unroot with SuperSu but it also did not work.