5.1 update bad signature

[pb5525]

I have a rooted (wugfresh) Nexus7 fhd. Build LRX22G Ver. 5.0.2 . I have had all other updates without problem. 5.1 keeps informing me that it is ready to download and install. Everything goes great, then while installing it always stops because system signature varification failure. Any ideas? And please don't respond with the obvious ," try turning it on first." Thanks Guys

 

[Rukbat]

It's finding the phone rooted, failing the "has this phone ever been rooted" check and stopping. The system signature (probably the MD5) of a rooted ROM is different that the system signature of an unrooted one.