why does firmware upgrade always fail?

[AC Question]

verizon galaxy note 3 is rooted. When i select it to perform the firmware upgrade it starts its process, reboots and in the booting process it fails to install the upgrade

 

[Rukbat]

rooted

That's why. You can't update a rooted ROM. (Things you can do while rooted can cause the update to brick the phone, so as soon as the "original never-been-rooted-ROM" test fails, the update fails.)

If you really want the update, you'll have to flash the stock ROM first (or just flash the version you want to update to and save a step - either way will wipe the phone, so back up anything you don't want to lose.)