WoW client screen glitching every hour or so

I run WoW classic in full screen windowed mode.
Since starting the MoP pre-expansion this Tuesday, about once or twice an hour my entire screen will blank out and start re-loading the entire U.I. piecemeal. The process only takes a few seconds, but it’s really annoying when it happens in the middle of a heated battle.

Anybody else seeing this?

Check your graphics settings. If the game is running in DX12, switch it to DX11. Fixed it for MoP Classic & Retail for me.