SHIELD OTA update failed to install.
If an OTA update on a SHIELD device fails to install, it may be due to the download of the OTA image becoming corrupted.
One way to resolve this is to delete the local data for the update from the device, forcing it to download a fresh copy.
To do so, use any file explorer app (such as ES File Explorer) to delete the OTA folder located in:
After this folder is deleted, reboot the device, then retry the download and installation of the update.