mobile

I'm on the AT&T D800 LG G2 on the stock ROM. Whenever I try to flash a new ROM it gives me that error. What do I do?
What I've done to get here:

• Use my G2 for a good while (back in Q3 2013)


• Install Mahdi 4.4 on it after taking a backup - everything's good.


• Fast forward to today


• Now I want to update it to 5.0+


• After taking a backup I wiped the caches, data and system partitions while keeping the internal storage, where I keep the ROMs and backups.


• Attempted to install Blisspop, CM12 or Resurrection Remix - Every one of those gave me that error. EXCEPT when I tried to update to a newer version of Mahdi. No problem at all. This leads me to think Mahdi has somehow managed to only allow Mahdi ROMs to be installed.


• Found the old backup before I flashed Mahdi, restored that. Now I'm back on an ancient stock ROM. (D800 10d)


• Attempting to flash a new 5.0+ ROM gives me the same error. What is going on?

I thought it was something Mahdi had changed in the build.prop file, so that's why I restored to this old version but it's still not working.