I have a verizon samsung galaxy s3. I'm planning to upgrade to the kitkat 4.4 but I was going to do a nandroid backup first. Using rom manager I am attempting to go into recovery mode but everytime I try I get this message: System software not authorized by Verizon Wireless has been found on your phone. Please turn off your phone and go to the nearest Verizon Wireless store for help. I disabled the knox sensor and then totally removed it and it's components. I don't know what else to try. Help?