Odd Gap in Thin Section

[Futz34 2]

I've got a thin section here on this cylindrical form I'm printing for a client. I'm not sure why it's printing a castle-like structure on the top. It should all be solid. Can someone take a look at my settings and see if there's something I need to change? Thank you in advance.

 

 

[Futz34 2]

Issue solved. I exported a finer resolution STL and that seemed to do the trick (if anyone was wondering).