[Solved] TWRP Unable To Open Zip and No OS in HTC Sensation

[YellowV]

Hello. I am trying to install a new Rom through TWRP but it returns the following error:

DEVICE: HTC Sensation
CURRENT OS: None
BOOTLOADER: Pyramid PVT Ship S-OFF RL
HBOOT VERSION:1.27.1100

Already Tried:

• 
  Check and uncheck zip file signature verification.

• Different Roms.

• Move zipped Rom from sd card to internal_sdcard and install it from there. (Does not end. The phone gets black after start copying the file.)

• Adb Sideload (Get stuck < waiting for device> although it initially recognizes 'my' phone in List of devices attached)

I'm new on this and I'd like already to thank your help.

Solution:
Installing recovery using fastboot