My HTC One M8 screen is blank and showing System UI Crashed

[amengaji]

Hi All,

Need urgent help....

I have an HTC One M8, which was working fine till a few day ago.
First a pop-up started appearing saying some android error. At first all I did was click "Don't send" (report to HTC) button. But it started coming regularly.
So I decided to restart my phone. Since then, the screen is completely blank with the following error:

"System UI has stopped unexpectedly. Would you like to send an error report to HTC. This is help us to improve our products."

There are no buttons, no background at all. It is completely blank.

I also tried a system restore function using "Power + Volume Down" The Recovery screen came up fine. When I selected "Recovery", The phone restarted with a blank screen with a icon of a phone and a Red Triangle with an Exclamation mark.

I tried it several times without success. I have lots of important data which I don't have a back-up for.

Would really appreciate your help.

 

[LeoRex]

I'll go rattle the cages of some HTC users I know.

 

[LeoRex]

If you are stuck in that recovery window... I think if you hold down the volume up button and hit the power button, it'll get you into the recovery menu.