The 5.0.x ROM is based on HTC’s latest M8 Sense 7 Android 6.0.x base and requires you to update your firmware to at least the 6.0.x (Marshmallow) version! If you don’t you will run into some issues such as Wi-Fi not working or No Boot, etc. 
We cannot install the firmware for you during ROM installation so you will need to take the steps to update the firmware on your own.

Note: Current ROM: ViperOneM8_5.0.2 is compatible with ALL carriers, click “info” below to see information regarding the ROM, carrier support, and issues.


 

Info about M8 MM ROM (5.0.x and up):

HTC has finally provided Android Marshmallow (6.0.x) with Sense 7 base for the M8, it came a bit later than promised by HTC but at least we now have official base to work from. We had provided Sense 7 ports based ViperOneM9 Marshmallow (MM) ROM as the newer device got the update before the M8 as was to be expected.  

Thankfully now the ports are over with the release of official MM for our device, even the US carriers (with the exception being AT&T) have provided an updated MM base with Sense 7, this allowed us to add US carrier support to our ROM.  Although ViperOneM8 5.0.x is fully based on latest MM update with Sense 7 for the M8, we have also ported some fixes, optimizations and additions from the M9 Android 6.0.x, Sense 7 base.  This has improved performance of the ROM and also allows our users to have a small taste of some improvements available on the M9 that the M8 did not receive. 

If you come from a native M8 Sense 7/ Android 6.0.x ROM, custom or not, you need to perform a full wipe prior to flashing ViperOneM8. The ROM is stable and currently works on all M8’s with at least 6.xx firmware, including the US carriers.

For the Marshmallow ROM(ViperOneM8_5.0.x and up) 6.xx firmware is required. HTC has released Marshmallow updates for the large majority of devices, most CID/ModelID . If HTC has released the Marshmallow updates for your CID/ModelID and you’re S-On you can return your device to stock and take the OTA’s, or you can flash the latest compatible RUU.  If you are S-Off there are a few other options you can take to update firmware, which you can see all around XDA (firmware only updates etc.).  Please be careful flashing firmware and ensure that it is compatible.  If you have a WWE device you may use the WWE 6.12.401.4 RUU/firmware, this is what is recommended and what the ROM is based on. Please be aware that you will need to be S-OFF if your phone is not a WWE phone!
Attention: CDMA devices cannot ever use any GSM RUU! Do not attempt to flash the RUU above on Sprint or Verizon phones! Never!

Below you see what carriers are supported and the known issues with ViperOneM8_5.0.2.

GSM/WWE: Fully supported

TmoUS: Supported with some carrier specific features (WiFi Calling etc.) – (known issues: voLTE & MMS over WiFi)

VZW: Fully supported

Sprint: Fully supported

ATT: Supported – Without carrier specific features. Users MUST choose “default” during installation.


 

ViperOneM8 5.0.2 

MD5: ffeecd08f6eada77f01357de6a5a6713
Main Link AFH

 

Previous roms


 

Incremental updates (OTA’s):

4.6.0 -> 4.6.1 Download
4.5.0 -> 4.6.0 Download
4.2.0 -> 4.3.0 Download
 4.1.0 -> 4.2.0 Download
 4.0.0 -> 4.1.0 Download

 

Previous OTAs

onclick = “if (! confirm(‘I have read the \’1.4x.401.x Firmware Requirements\’ above the download links and I\’m aware that I will encounter reboots after turning off the screen if I didn\’t read and follow those instructions.’)) { return false; }”