How can I rollback my HTC M8 to KitKat ?

[AC Question]

Got Lollipop update yesterday - and two way call recording app ACR stopped working.

ACR makers told:
"HTC M8 stopped supporting normal call recording with Android 5. But here seems to be a way to get around this issue. We are investigating to see if we can achieve this with ACR. In the meantime you might want to try other call recording apps. I am sorry about this inconvenience but it is out of control. Manufacturer make undocumented changes."

Then I tried different call recorders but non of them worked.

It is very important to me to have this function available ( Two way call recording was actually the reason I got that expensive M8 at first place )

Any thoughts?

 

[Rukbat]

You can't "roll back" an update, because there's no "rollback" file, and the 4.4 firmware that used to be in the phone isn't there any more - it's been replaced with Lollipop firmware. You'll have to find a 4.4.4 or earlier ROM (whatever you were running before, to make sure the app works with it) and flash it. This will overwrite everything on the phone so if you don't have everything backed up all the time (which you should - the next time the phone slips in your hand it could be out of your hand and under a moving truck tire in a second and there goes all your data), do it before you flash the ROM.

Sorry, but I can't give you links to ROM files or tutorials - I don't know HTC at that level, and every manufacturer does it differently. (The M8 forum on XDA Forums for your carrier [just put M8 into the "Type to find device" box] might have everything you need.)