Wall Cap Serious Error

[mtldesigns]

Sending this to tech...

 

Wondering if others get the same message.  Its only when I am adding a new cap to a railing/half wall.  Worked this model all day  without an issue.  I even saved, got out of Chief, reloaded and the first step was this, to the same error message

 

By the knowledge base, I should be good with everything.. latest version, plenty of vid card and ram, model is on hard drive..etc....