This just started happening. I try to export or render, and I get glitches/snow instead of the image. When I go to the export window (see screengrab below), the image is distorted. The glitches/snow also appear on the exported movie file. I've been using this version of Premiere (2017) for over a year and never had any problems. This is happening with different projects, including projects I had exported in the past with no problems.