It's been around for a while, but I thought it was fixed in 2009.
IIRC it's caused by deleting a camera with correction while the viewport is set to that camera.
Create a new camera, switch the viewport to that camera, then delete the new camera. Viewport should be back to normal.
This thread is where I found the info.
Max 2016 (SP1/EXT1)
Win7Pro x64 (SP1). i5-3570K @ 4.4GHz, 8Gb Ram, DX11.
nVidia GTX760 (2GB) (Driver 430.86).