ideamaker 3.1 not importing STL properly

[sperman]

When importing an STL file, the software is creating geometry that doesn't exist.

Here is the file in cad.

cad.JPG (18.99 KiB) Viewed 148 times

And this is what it looks like in the slicer.

slicer.JPG (14.14 KiB) Viewed 148 times

The brown stuff doesn't exist in the STL. (I've checked it with other slicers.) I thought it was just an graphics card anomaly, but when I sent it to the printer, it started printing it as well.

This happens as soon as I import the STL model, before any slicing takes place.

[sperman]

Correction. The brown section appears once I "repair" the model.