Found a way
Originally Posted by sijofrancisza
Have a bit of a problem. Have a HTCOne Dev Ed. Android 4.4. Had to encrypt to allow work exchange mail to work. Has also been rooted and has TWRP recovery.
Now have a problem. Because of encryption, cannot mount the drive in TWRP. Also means cannot get OTA updates to work. Cannot do a factory reset either.
As I see it, only way to remove encryption and restore to factory stock would be to S-off and run a RUU of the stock. Does anyone have any other suggestions? Also, would rumrunner run into any problems due to the encryption. Don;t really want to brick a functioning phone.
Right folks, I have found a way thanks to everyone who posts on this site and other similar ones. Can't get S-Off with rumrunner without removing encryption and getting rid of screen lock. Cannot flash a new ROM or restore stock ROM without S-Off.
Step 1: Have to change TWRP to Clockwork Mod recovery. Then go to the Mount and Storage page, and choose "format /data and format /data/media" option at the bottom of the list of options. Once formatted,
Step 2: For some reason even after removing the pin to unlock screen, Rumrunner would not work. Eventually found out about Firewater from pradeepvizz's post on XDA-Developers.. This got S-off
Step 3: Flash a new ROM. I decided to try the GPE ROM. Although for some reason this got stuck after the first pass on my computer with Win 8. Worked fine when tried again on a Win 7 PC.
Took about 4-5 hours to do this but I couldn't have figured it out without all the folks who post on this and similar sites. Thanks to all.