Weird surfaces showing up

[cash68]

I'm importing a Pro E 4 file (can't share it, confidential for a major client) and I'm getting these bizarre surfaces showing up, that do not exist at all in Pro E.  When I exported to a step file, it imports perfectly.  Other surfaces are basically missing sections.   Why?  I've tried adjusting tessellation both up and down, no difference. 

[Chad Holton]

Hmm.. can you share a screenshot? Maybe one that's not too revealing of the part (being confidential and all) but shows these surfaces. Did you make this part? Just curious if it were made starting with surfacing features or something... or anything else that may give us more clues.

[guest84672]

Could be related to bad geometry. Are these surfaces imported into Pro/E by any chance?