Note 4 N910C Reactivation Lock Problem

I have Note 4 N910C with android 6.0.1 version. Reactivation Lock enabled when i downgrade from marshmallow to lolliop and type any samsung account on reactivation lock its working and phone unlocked but not disable permanent when i uncheck reactivation lock on security option and the password of account but not uncheck reactivation lock. When i upgrade from lollipop to marshmallow and type my email which i used on lollipop but its not working and this error come "Processing Failed"
What is the solution
And this mobile also problem with DRK on recovery mode and i can’t flash any root file becasue Reactivation enabled.