stuck in fastbot

[Mrlibya]

Hello , i've HTC one m8 was running on cyanogenmod so i was want uninstall it and install the official rom so i've relocked the botloader then the RUU(RUU_M8_UL_M60_SENSE70_ATT_MR_Cingular_US_6.20.502.5_combined) was not apply to install ( when it's start to install it's says check your phone is connectd or not ) and i got stuck in the fastbot and my usb debugging set to off
what i should do ?

photo of my phone:

 

[ScottsoNJ]

I think the bootloader needs to be unlocked to flash anything and THEN after flashing you relock it

 

[Mrlibya]

I think the bootloader needs to be unlocked to flash anything and THEN after flashing you relock it

and how i can do that?