I have a rooted Rogers (Canadian) D803 and tried to install twrp-184.108.40.206-g2rog.img recovery from TWRP, Flashy and Nandroid apps. All report the replacement was successful but if I try booting to recovery "secure booting error" appears for 20-30 sec then black screen. The phone is still on because the display backlighting is barely visible. Holding down power button for 10-13 sec then restarts to KitKat. There must be hundreds of posts related to twrp recovery problems and efforts to unbrick or return to stock (and I've read 5-6 hrs of them). Can't seem to find a reason for these secure booting error recovery problems. Can someone explain WHY this happens.