First some info:
I have a non-rooted XPE 1575 with an unlocked bootloader. I have never been able to receive an OTA update and needed to install 6.0 using a clean install of a stock ROM. I now can not successfully install the security OTA update (i get a dead Andy ‘Error’). I have flashed stock recovery, boot image, and system chunks. No luck.
More alarming to me (and possibly a hint at what is going on) is that i can not even back up my phone using TWRP (v2.8.7.0). My internal memory is too small for this, so when i try backing up to my 128 GB sdcard (formatted to be adaptable), i get the following error E: Unable to create folder: /external_sd/TWRP/BACKUPS (errorno=5) E: Failed to make backup folder.
So, i can’t stay ‘stock-like’ and just use OTA updates, and i can’t backup my phone and then try to install a clean updated ROM.
Any ideas from anyone?