How do I open a Certificate Trust List file?

I downloaded a file off of, a 3d modeling file. It says "this file is invalid for use as the following: Certificate Trust List"
Please help, any info helps.

What program are you trying to open the file with?
theboygenius (author)  mpilchfamily4 years ago
i feel dumb now, i haven't been using one, what do you suggest,
Whatever software came with your 3D printer. If you downloaded an STL file, then you could also open it with Autodesk 123D, Sketchup, or some other 3D modelling software to see what the object would look like.
theboygenius (author)  kelseymh4 years ago