A chunk of my print is missing

[TunixG 0]

Hi, I'm new to 3D printing and I've been trying to print this mandalorian helmet but for some reason the layers on my model wont show up when slicing and many of the layers will simply disappear. I'm attaching the stl and blender file so anyone can see it. Thanks in advance for your help.

 

 

untitled.stlblender file.zip

[GregValiant 1,330]

The model has a lot of surfaces that are facing inside-out.  It needs to be repaired.  In Blender check the color of all the surfaces that show up red in the Cura preview.  I think you can flip them around there.

The model is made up of a bunch of sub-models.  They all have errors.