Everytime I try to view this model sectioned with the top plane I get an error. I can't figure out what is wrong. I've attached the file and screen shots. Thanks for any help.
This area in particular seems to be poorly modeled.
I think I would use this model only for reference and start over from scratch.
Notice that plane through original geometry returns incorrect section (previews OK, but then result is not correct).
It likely means there is a very small piece of zero thickness generated if you cut it at this section plane. Try moving it over a bit (.00001").
I'm getting the same results you are (I believe this is a bug) but there are two work-arounds you can use until it gets fixed:
Hope this helps for now.
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