# Nexus 6 OTA from 5.0.1 to 5.1 fails - Error in block.map

I am trying to upgrade my Nexus 6 with version 5.0.1 (Build number LRX22C) via OTA to Android 5.1.

The OTA update is downloaded successfully and after pressing "Restart & Install" I see a dead droid with the message "Error!".

The phone was rooted and I unrooted it via SuperSU. Did not help. Wiping cache partition also did not change anything.

These are the logs:

Finding update package..
Opening update package..
Verifying update package..
Installing update..
Verifying current system..
/dev/block/platform/msm_sdcc.1/by-name/system has been remounted R/W: reflash device to reenable OTA updates
E: Error in 0/cache/recovery/block.map
(Status 7)

Installation aborted.


I would really like to upgrade without wiping the data.

• Same problem here but with a Nexus 5. I upgraded from 4.4 to 5.0.1 while rooted (had to re-root afterwards of course) without any problems, so I guess it's a bug in this upgrade. Might have to wait for a fix once Google realise what's broken. – Malvineous Apr 8 '15 at 6:02
• @Malvineous - It's not a bug, it's intentional. It's a security precaution so potential security vulnerabilities don't get passed into a new version. SuperSU/root is technically a huge security vulnerability as is having an unlocked bootloader. What you have to do is reflash that versions system.img again to get it back to stock and then the OTA will go through fine assuming you also reflashed the stock recovery. After the OTA you can re-root/TWRP. – Enigma Aug 13 '15 at 14:25
• @Enigma: Yep I worked that out in the end - it's a shame they don't have a more helpful error message. Rather than reflash the system.img I just uninstalled SuperSU and renamed a few of its backup files back to their original filenames through the shell, and this allowed the OTA upgrade to proceed. – Malvineous Aug 14 '15 at 6:36