I used this method to root my phone.http://forum.xda-developers.com/show....php?t=2699065
I now have S-off and twrp 126.96.36.199-m8 installed. I am using the at&t stock 4.4.4 recovery that came with this method.
I downloaded the twrp android_device_htc_m8-android-5.0.zip and tried to install it from the twrp recovery and it failed.
I did wipe cache/dalvik also.
Sorry for being such a noob.
What is the easiest way to keep root and get lollipop?