Rendering Hiccups When Not Using OpenGL - White Planes of Doom

[loretta.at.large]

So this is my first post ever, though I've been checking the forums for a while.  Occasionally when I'm rendering a viewport at a higher quality setting (not OpenGL), everything will be going just hunky dory.  Then I decide to render another viewport and Vectorworks quickly shows me a series of white planes against a black background that make me want to throw my mouse at the monitor!  I think this has been covered by the forum, but I'm wondering if anyone has come up with a reliable solution that goes beyond having to shut down Vectorworks and reopen it everytime this happens.  The first screenshot shows an example of a problem rendering.  The second screenshot is one that rendered just fine a minute prior.    

Edited November 15, 2018 by loretta.at.large