Strange lines on screen only in Time Machine
I have some strange vertical and horizontal lines when I enter in Time Machine.
I've checked for errors on the the graphic card but it's working fine.
Specs:
macOS Sierra 10.12 (16A320)
iMac (Retina 5K, 27-inch, Late 2015)
iMac with Retina 5K display, macOS Sierra (10.12)