I have a Samsung Note II, 4.4 Kit Kat caused my phone to lock on reboot following the update. Sprint store repairs say there is nothing they can do and referred me to Samsung Mobile store, said they may be able to force a restore of the factory rom. Have tried a manual restore via Kies with no luck.... Expensive paper weight with no resolution from Sprint... Best they could do was recommend I change my plan and purchase a new phone at full price... Sprint Store said don't even try Sprint Customer Service, they won't do anything for you except forward your call around until you get disconnected...
So, what to do?
i had the same issue. Here is what i did and it helped me.
Hope it helps you.
You saved my phone! Thanks for the link, worked perfectly. I had tried several other attempts at flashing back to factory restore but all failed. This brought me back like the kit kat update didn't even happen! Like everything these days, if you can't fix it yourself your out of luck...Thanks again, and NO thanks to Sprint, just sayin...