I get this error when I try to run my analysis using a high quality mesh. It runs fine with a draft quality mesh, so I am thinking it is some issue related to the mid-side nodes. I have an SPR for this (586951), but am wondering if anyone else has encountered this and has a work around.
My analysis is an assembly containing surface models, since I am analyzing carbon fiber composite parts. Let me know if anymore information would be helpful.
I would check all the definitions for the lamianted materials and the ply schedule. could be an error in there. Of course this does not explain why it would run with tria 3s and not with tria 6's.