AE Preview window black - goes black when making window wider

Since the v24 update, the playback window goes black if I make it wider than the video width at 100%.

I can adjust the window height to any size with no issue.

If I adjust the zoom to greater than 100%, it still blanks at what would be the width at 100%

I also just started getting an error on AE startup:  "Mercury 3D is not supported by the current hardware." - I don't know if or how it could be related.