I have a SM-900A on MJ5, not rooted, on ultra mobile (t-mobile)
1. software update says there is no update available.
2. i tried 240258.zip (or something - renamed to update.zip) in sd card...Install from external storage...gives me some error about keys not matching, wipes /data and reboots
The guide to go up to 4.4.2 over here uses a UrDroid rooted 4.4.2 after safestrap. But that was back in Apr 2014 when towelroot was not available.
Where can i just download the correct update.zip and do a stock upgrade to 4.4.2? i do want to root after it but i am assuming towelroot should work without a hiccup. Am i missing something here?