[One (M8) Q&A, Help & Troubleshooting] gemejiar:
I followed the instructions of this page:

http://xdaforums.com/att-htc-one-m8/development/att-4-4-3-2-22-1540-3-debloated-sense-6-t2837365

Results of this process are:

C:\fastboot>fastboot oem rebootRUU

... (bootloader) Start Verify: 0

OKAY

Execution time is 20(ms)

C:\fastboot>fastboot flash zip 428_firmware.zip

sending 'zip'... (36029 KB) OKAY

sending time = 2.235 secs

writing 'zip'... (bootloader) zip header checking...

(bootloader) zip info parsing...

(bootloader) checking model ID...

(bootloader) checking custom ID...

(bootloader) start image[hboot] unzipping for pre-update check...

(bootloader) total_image_number=8

(bootloader) start image[hboot] flushing...

(bootloader) [RUU]WP,hboot,0

(bootloader) [RUU]WP,hboot,99

(bootloader) [RUU]WP,hboot,100

(bootloader) ...... Successful

(bootloader) current_image_number=0

(bootloader) current_image_number=1

(bootloader) current_image_number=2

(bootloader) current_image_number=3

(bootloader) current_image_number=4

(bootloader) current_image_number=5

(bootloader) current_image_number=6

(bootloader) current_image_number=7

FAIL90 hboot pre-update! please flush image again immediately

FAILED (remote: 90 hboot pre-update! please flush image again immediately)

For "hboot-preupdate" response, restart the same procedure for device HT46KWM01

62...

sending 'zip'... (36029 KB) OKAY

sending time = 2.239 secs

writing 'zip'... (bootloader) zip header checking...

(bootloader) zip info parsing...

(bootloader) checking model ID...

(bootloader) checking custom ID...

(bootloader) total_image_number=11

(bootloader) start image[boot] unzipping & flushing...

(bootloader) [RUU]UZ,boot,0

(bootloader) [RUU]UZ,boot,13

(bootloader) [RUU]UZ,boot,23

(bootloader) [RUU]UZ,boot,36

(bootloader) [RUU]UZ,boot,49

(bootloader) [RUU]UZ,boot,59

(bootloader) [RUU]UZ,boot,69

(bootloader) [RUU]UZ,boot,81

(bootloader) [RUU]UZ,boot,93

(bootloader) [RUU]UZ,boot,100

(bootloader) [RUU]WP,boot,0

(bootloader) [RUU]WP,boot,100

(bootloader) ...... Successful

(bootloader) current_image_number=0

(bootloader) start image[rpm] unzipping & flushing...

(bootloader) [RUU]UZ,rpm,0

(bootloader) [RUU]UZ,rpm,100

(bootloader) [RUU]WP,rpm,0

(bootloader) [RUU]WP,rpm,100

(bootloader) ...... Successful

(bootloader) current_image_number=1

(bootloader) start image[sbl1] unzipping & flushing...

(bootloader) [RUU]UZ,sbl1,0

(bootloader) [RUU]UZ,sbl1,100

(bootloader) signature checking...

(bootloader) verified fail

(bootloader) ..... Bypassed

(bootloader) current_image_number=2

(bootloader) start image[sbl1] unzipping & flushing...

(bootloader) [RUU]UZ,sbl1,0

(bootloader) [RUU]UZ,sbl1,100

(bootloader) signature checking...

(bootloader) verified fail

(bootloader) ..... Bypassed

(bootloader) current_image_number=3

(bootloader) start image[sbl1] unzipping & flushing...

(bootloader) [RUU]UZ,sbl1,0

(bootloader) [RUU]UZ,sbl1,100

(bootloader) signature checking...

(bootloader) [RUU]WP,sbl1,0

(bootloader) [RUU]WP,sbl1,100

(bootloader) ...... Successful

(bootloader) current_image_number=4

(bootloader) start image[sbl1] unzipping & flushing...

(bootloader) [RUU]UZ,sbl1,0

(bootloader) [RUU]UZ,sbl1,100

(bootloader) signature checking...

(bootloader) verified fail

(bootloader) ..... Bypassed

(bootloader) current_image_number=5

(bootloader) start image[sensor_hub] unzipping & flushing...

(bootloader) [RUU]UZ,sensor_hub,0

(bootloader) [RUU]UZ,sensor_hub,100

(bootloader) [RUU]WP,sensor_hub,0

(bootloader) [RUU]WP,sensor_hub,4

(bootloader) [RUU]WP,sensor_hub,8

(bootloader) [RUU]WP,sensor_hub,12

(bootloader) [RUU]WP,sensor_hub,16

(bootloader) [RUU]WP,sensor_hub,20

(bootloader) [RUU]WP,sensor_hub,24

(bootloader) [RUU]WP,sensor_hub,28

(bootloader) [RUU]WP,sensor_hub,32

(bootloader) [RUU]WP,sensor_hub,36

(bootloader) [RUU]WP,sensor_hub,40

(bootloader) [RUU]WP,sensor_hub,44

(bootloader) [RUU]WP,sensor_hub,48

(bootloader) [RUU]WP,sensor_hub,52

(bootloader) [RUU]WP,sensor_hub,56

(bootloader) [RUU]WP,sensor_hub,60

(bootloader) [RUU]WP,sensor_hub,64

(bootloader) [RUU]WP,sensor_hub,68

(bootloader) [RUU]WP,sensor_hub,72

(bootloader) [RUU]WP,sensor_hub,76

(bootloader) [RUU]WP,sensor_hub,80

(bootloader) [RUU]WP,sensor_hub,84

(bootloader) [RUU]WP,sensor_hub,88

(bootloader) [RUU]WP,sensor_hub,92

(bootloader) [RUU]WP,sensor_hub,96

(bootloader) [RUU]WP,sensor_hub,100

(bootloader) ...... Successful

(bootloader) current_image_number=6

(bootloader) start image[tz] unzipping & flushing...

(bootloader) ...... Successful

(bootloader) current_image_number=7

(bootloader) start image[wcnss] unzipping & flushing...

(bootloader) ...... Successful

(bootloader) current_image_number=8

(bootloader) start image[radio] unzipping & flushing...

(bootloader) trying to rename MBA

(bootloader) ...... Successful

(bootloader) current_image_number=9

(bootloader) start image[rcdata] unzipping & flushing...

(bootloader) ...... Successful

(bootloader) current_image_number=10

OKAY

Flash Zip Complete

Execution time is 58(s)

C:\fastboot>fastboot reboot-bootloader

rebooting into bootloader... OKAY

Execution time is 14(ms)

C:\fastboot>fastboot flash recovery twrp-2.8.6.0-m8.img

sending 'recovery' (17034 KB)... OKAY

writing 'recovery'... OKAY

Execution time is 3(s)

C:\fastboot>

When i want to enter in recovery mode (TWRP), the phone turns off.

Please you see the video in youtube with this title "M8 AT&T, boot loop, recovery doesn't work. HBOOT work fine V2"

this other video show the previos state of cellphone (see in youtube "M8 AT&T, boot loop, recovery doesn't work. HBOOT work fine")

What do you think?

Can I install a Stock Backups?

the stock backups restores partitions correctly?

Help me please, i do not know what I need to do!!:(