Slice and Dice....STL to x3g Errors

[aoibydesign]

I'm new to 3d printing but have been using some design software for years.
I've printed some "things" successfully but now I have an original model and
I cannot figure out what I'm doing wrong. The stl file looks good in multiple
software programs and always when going from stl to x3g it creates fill in my open
areas messing up the design. I rebuilt from scratch completely and got the same result.
I think its the rounded corners? Any suggestions?


cross case 5.stl

[Polygonica]

The file contains open edges, self intersections, and multiple shells. Any one of these can make it not printable.

cross case 5.jpg

You need to fix the file before printing; our Polygonica software does this automatically in a matter of seconds.

cross case 5_PGFIXED.stl