MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
As 3DGuardian mentioned, the thighs are not printing as a solid piece, only the walls.
I added a remix with the fixed files. The instructions on how I did this are below.
Open in Meshmixer
Go To Edit -> Make Solid
Use These settings:
Solid Type => Accurate
Solid Accuracy => 512
Mesh Density => 512
Offset Distance -> 0.5mm (this is the important setting, which you can try playing with)
Export as binary .stl
Import into your slicer and confirm that it's printing as a solid.