I installed astrometry.net locally and to test it I set up a new sequence. Under target settings, I pointed to an image I have on my hard drive for “reference data” and hit blind solve. SGP then gives a plate solve error saying “No reference image selected”. I tried it with jpg, tif and cr2 files. Maybe I’m just doing something wrong because I usually use the framing and mosaic wizard and haven’t done it this way in a while.
You are not out of your mind. We accidentally left many unsupported file types in the target settings box. Right now we only support unsigned 16 bit FITS image files. We may support more in a future release.