AT&T HTC One M7 - In TWRP No OS Installed after formatting , what happened?

[AC Question]

AT&T HTC One M7 - In TWRP No OS Installed after formatting data

I've been having a lot of trouble with my HTC One lately and decided to format data and then was planning on reinstalling the Android Revolution HD ROM that I've been using. In formatting though I lost the file and am now sitting with only TWRP installed and no file to flash. Is there any way to recover from this?

 

[Rukbat]

Re: AT&T HTC One M7 - In TWRP No OS Installed after formatting data

You probably didn't notice that System was checked when you formatted.

You'll have to find a flashable file and a tool to flash it (or a TWRP system backup). I'd try HTC One (M7) - XDA Forums first.