Illustrator not rendering 3D correctly - Missing pieces

[b3nnie]

Parts of the artwork seem to be missing when I render it in 3D

[Monika Gause]

Any warnings about overlapping geometry?

[b3nnie]

I haven't seen any sort of warning

[tromboniator]

Whether or not you've seen an intersection warning, a very slight rotation can sometimes fix this problem.

Before:

After:

Peter

[Mike_Gondek]

Is that a black fill with red stroke. Instead do a 3d on 2 fills 

1. black fill on top
2. red fill underneath that is offset path and expanded by the amount of the stroke

The 3d tranform does not like strokes, and is pretty buggy in Illustrator, especaily as the #D extrusion get more complex.