If the device boots into maintenance mode continuously(it means you cannot boot up the system, and the device into maintenance mode repeatedly), reverting or reinstalling PAN-OS may fix the issue. This document describes how to revert or reinstall PAN-OS from maintenance mode.
The current active version of PAN-OS and the revertible version of OS will be available.
Select the appropriate action (revert/reinstall). Both revert and reinstall load PAN-OS on the alternate sysroot partition.
Once the revert/reinstall operation is complete, a message shows up if the action resulted in success or failure. Once the action succeeds, go ahead and reboot the device from the maintenance recovery tool.
The device can now reboot on the other sysroot partition with the reinstalled/reverted PAN-OS.
Note: Be aware that the reverted PAN-OS uses the configuration that was stored with that PAN-OS image.