[Q] Can't install Lollipop OTA, Recovery fails topic

So a few months back I tried CyanogenMod and found out I ultimately prefer Sense. So I tried to return to it and had some troubles along the way. I finally made it back to stock with the help of some lovely XDA members. However, now when I try to install the OTA, a red symbol appears on the recovery screen. What's wrong?

Previous thread: http://forum.xda-developers.com/htc-...ocked-t2922700

The info on my bootloader screen is

M7_UL PVT SHIP S-ON RH
HBOOT-1.57.0000
RADIO-4A.17.3250.14
OpenDSP-v32.120.274.0909
OS-6.14.771.2
eMMC-boot 2048MB