Originally Posted by jdlaser
I am currently running jellybeans ver21 on android 4.1.2. Can I just use odin and upgrade the MJ9 firmware then wipe and load new roms using the newest firmware or do I have to go back to stock first?
From what I read (because I have the MJ9), having 4.1.2 with MJ9 can either cause messy problems with some apps and sms/mms/calls/data/etc. or works perfectly fine (usually when you flash a custom ROM).
I haven't done it myself but you're more than welcome to do a complete backup of everything on your phone and flash MJ9.
Best of luck to you.