Compilation Warnings - no model visible in OpenSCAD

[StigZord]

I have followed design generation steps, but can't correctly open them in OpenSCAD.

Here is what happens:

I run lein auto generate
I get the message: auto> Complete
Open OpenSCAD select any of the .scad files, for example switch-plates-right.scad

In the OpenSCAD console I see following warnings:

Compiling design (CSG Tree generation)...
[WARNING: Ignoring unknown variable 'scad' in file switch-plates-right.scad, line 67466]
[WARNING: Ignoring unknown variable 'clj' in file switch-plates-right.scad, line 67466]
[WARNING: Ignoring unknown variable 'cut' in file switch-plates-right.scad, line 67466]
[WARNING: undefined operation (undefined / undefined) in file switch-plates-right.scad, line 67466]
[WARNING: undefined operation (undefined - undefined) in file switch-plates-right.scad, line 67466
Compiling design (CSG Products generation)...
Geometries in cache: 4328
Geometry cache size in bytes: 4033368
CGAL Polyhedrons in cache: 0
CGAL cache size in bytes: 0
Compiling design (CSG Products normalization)...
WARNING: Normalized tree is growing past 200000 elements. Aborting normalization.  
WARNING: CSG normalization resulted in an empty tree 
Normalized tree has 0 elements!
Compile and preview finished.
Total rendering time: 0:00:02.179

and there isn't any model present in the preview window.

Am I doing something wrong?

[dereknheiley]

This is the important part.
WARNING: Normalized tree is growing past 200000 elements. Aborting normalization.
WARNING: CSG normalization resulted in an empty tree
Normalized tree has 0 elements!

I take a pretty lazy approach to performance tuning. Which is to say, i don't for casual things.

I got around this issue by increasing these values in the scad program preferences.
NOTE: you will probably have to increase OpenSCAD params:
Turn off rendering at ~10,000,000 <----- this one needs to be higher, scad is giving up because it's currently at 200k
CGAL cache size ~8000mb
PolySet cache size ~8000mb