Currently my Nexus 5 is on Android M preview. I know that developer preview won't get the OTA update, that's why I am trying to manually install OTA of Android M public release, but I get these errors on 50%:

failed to verify whole-file signature 
signature verification failed Installation aborted

adding more details:

no root
no custom recovery
just bootloader unlocked
no changes in system files

Does manually installing Android M final release OTA work on device running on Android M preview? Or do I need to downgrade it to Lollipop first?

  • Have you rooted the device or flashed a custom recovery? Commented Oct 12, 2015 at 13:26
  • 1
    Which recovery are you using? See if there is an option to disable signature verification.
    – Firelord
    Commented Oct 12, 2015 at 16:58
  • @AndrewT. i know i will not get ota update, thats why i am trying to manually install OTA, do you have any hint of any solution to my problem?
    – Yogi
    Commented Oct 16, 2015 at 9:18
  • 1
    I can't say for sure, but I believe for technical reason you can't, because the OTA is meant for Lollipop, not Marshmallow preview. You have to flash the whole image. (that statement is included in the dupe)
    – Andrew T.
    Commented Oct 16, 2015 at 9:59

2 Answers 2


Short answer: You can't.

OTA update is built for specific build model. As far as I can find, Google only provides OTA update for Android 5.1.1 Lollipop users (e.g. article on Digital Trends, article on Android Central).

In addition of that, Google has already mention that there is no OTA update for developer preview to stable version (refer to Will the Android M developer preview get an OTA update to the stable release version?).

So, either you must flash the final Marshmallow image from Google's Factory Images for Nexus Devices, or downgrade to Lollipop and install the OTA (for whatever reason, because I think it's impractical since you have unlocked bootloader anyway).

  • I provided my answer based on my knowledge. If there's indeed a way to install the OTA for developer preview (perhaps modded OTA?), feel free to provide the answer!
    – Andrew T.
    Commented Oct 18, 2015 at 15:17

You need to give more details about what you have tried, from the error you have received it seems like you have not done an OEM unlock on the device with fastboot.

There are steps you first need to do before this

  1. Enable developer options (tap on the build number in About Phone 7 times).

  2. In developer options, enable OEM unlocking.

  3. Switch the phone on in the fastboot menu (by holding power and volume button).

  4. Run the command

    fastboot oem unlock

from your computer

  1. Now it should be possible to flash the ROM using the instructions.

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