"Unable to load file" when printing over USB

[rmsailors]

Please help a Simplify3D newbie.

When trying to print a moderately complex model on a XYZPrinting Da Vinci Pro 3-in-1 (model is roughly: x 40mm, y 62mm, z 100 mm)
The print preparation process seems to complete smoothly, but when I try to print via USB, I get an error that says "Unable to load file" (paraphrasing).

I am trying to print with rafts and supports turned on.
Layer 0.20 mm
Top 4 layers
Bottom 4 layers
Outline shells 3
Honeycomb fill @ 60%

I am able to save to a file.

thanks in advance

[cstraley]

check what com port you are using then go to machine control panel and make sure that the baud rate and the com port is set right .