After installing a few stencils from Stenciltown, the stencil that shows up in Omnigraffle Pro on Mac (6.6) shows each object as a question mark. For instance, both of the Google Material Design Icons stencils as well as the Font Awesome stencil are like this for me. I was able to clear them up by going out and separately downloading and installing the Google Material Design Icons font (.ttf file) and Font Awesome font (.otf file) via Mac’s Font Book app. It would have helped a great deal if Stenciltown had provide some guidance on installing these stencils, namely that additional font installs were necessary. Also, it only seems logical that you would require support contact info from the folks uploading stencils to Stenciltown in case there are questions.
I also wonder about the two Material Design stencils, google-material-design-icons and google-material-design-icons-1. They seem to contain the same icons although its hard to tell since they have a large number of icons. Was the “google-material-design-icons-1” stencil meant as a replacement of the google-material-design-icons? Again, a little more descriptive info in Stenciltown would tell us what to expect.