Do not fear! This exact problem happened to me. The only solution is to go back to s-off, factory reset, and RUU. Unfortunately when I did it I only had the oldest RUU (1.15) so I had to HTC dev unlock my bootloader and now it says tampered. There are newer RUUs now so that shouldn't be a problem.
If there's anything you want me to clarify just ask.
Sent from my HTC6435LVW using xda app-developers app
---------- Post added at 06:27 AM ---------- Previous post was at 06:25 AM ----------
The reason RUU isn't working for you is because you have to flash hboot. There's a thread on it somewhere but If you can't find it I'll post the link tommorow. I think it's the s-on to s-off thread.
This is the thread:
[How-To] From S-OFF to 100% Stock S-ON [Facepalm/JTAG/RevOne/Moonshine]
This part fixes the RUU error:
FLASHING THE STOCK HBOOT:
*Credit to .torrented*
1. download 1.15 stock hboot: 1.15 stock hboot MD5: B4B8555C20724E12C3B9D33820746E50
2. Rename stock hboot file to : PL83IMG.zip and place in the folder that contains your fastboot.exe file (On your computer)
3. Flash hboot