When selecting a generic resource it attempts to open an empty Resource Viewer. I checked that "No viewer" is set in the Sidora configuration for the content mode. If trying to "Open In a New Window" is selected the user gets an message that, while not user friendly, is correct. I am going to open a new issue for this rather than reopen this issue since this is minor.

Either the behavior should be the same as "Open in a New Window" or the Generic object could use the OBJ mime or FITS if present to try to open a viewer that will work with kind of resource.  The design of SIdora is to use the type to select the viewer so this second approach would add to functionality are require more work.