D750 tethered live view blown out

[LPTT1]

I have a d750 that I've successfully been shooting tethered sessions with for a year. I've hit some new glitch and when tethered, my live view is totally blown out. It's happening in both LRC and Capture One. The camera is taking properly exposed images. It's just the live view that is unusable. I can not figure out why this is happening. I thought it was LRC but it's also happening in Capture One so it's something with the camera. Help?!

 

[BF Hammer]

I have to take a very wild guess by reading between the lines. Is there an aperture control ring on the lens you are using? Remember to set it to the highest f-stop so the camera body can control that properly.

 

[Needa]

Maybe monitor brightness? I-menu option