Originally Posted by uf21
When did Samsung start doing this? When I had my s3 I was able to downgrade to any version but now I can't even downgrade at all. This is really frustrating. Now I'm stuck on a firmware that cripples my GPS.
samsung started this stuff when they started to use KNOX.
They agressively update the bootloader for any patches useful to protect their system evironment. Therefore, in KK, AFAIK, any changes of the firmware letter, means new bootloader.
what most of users do normally (if they have a rooted device), is just flash a newer custom ROM, and stay with their old bootloader (KK). By doing this way, you still can jump any older custom ROM base without any problem.
But once you flash a new original firmware, it will flash the new bootloader as well. And it is non-downgradable.