I just used the RUU.exe to return to at&t stock software number 1.58.502.1
Kind of did things the hard way, although you are back up and running. Now you will need to unlock the bootloader and install custom recovery again, to get back to where you were.
All you really needed to do was either restore your nandroid (you should always make one before flashing anything) or get a different ROM (Sense 1.xxx base) onto the phone and flash it.
Also, the phone was likely not really "stuck", just taking a REALLY LONG time to boot, like 10 minutes.
I've read exactly what you said about being on Sense 2.22 but that's where I'm not sure what to do since AT&T hasn't release 4.4.3 yet and theres nothing for me to update to.
The post I linked previously includes the specific firmware package for US users, and a link to detailed instructions. 2.22.1540 is what you want to use, its pulled from the US Dev Edition OTA. While its not the "official AT&T" firmware, the DE is identical to the AT&T version in everything except AT&T branding (band support, etc.) and designed specifically for use on AT&T. Users here (including myself) can confirm it works seamlessly on the AT&T version.
2.22.1540 is also specifically advocated for use on the AT&T version in the following ROM post, along with great instruction (this is personally the one I used). Although you have to download the whole ROM, as the firmware is packed with it:
http://xdaforums.com/att-htc-one-m8/development/att-4-4-3-2-22-1540-3-debloated-sense-6-t2837365
Do I have to S-off to obtain Sense 2.22?
To update the firmware as I've described, yes. Reason being, the partitions that need to be updated by the firmware (radio, hboot, etc.) can't be modified without either S-off, or "official" update meant for your version.
The other option is to remain S-on and wait until AT&T releases the OTA. But who knows when that will be . . .
And also how difficult is it to S-ON?
S-on isn't really necessary. As long as you understand the implications of s-off, its usually better to be s-off. More freedom, and more options to recover if you have issues.
Also, AT&T doesn't care about s-off in terms of warranty service. They only care about physical damage or water damage.
Again thanks so much. I see you helping a lot people here redpoint so first of all thanks
No problem at all. I've benefited a lot from XDA, and its my way of contributing.
