Rear disk touches the caliper mount I am putting a new caliper on and the had to get an adapter.  Anybody know why it rubs and how to solve it?
I see the rotor hitting the caliper near the mounting area. The caliper has been moved all the way over on its slots, but the pictures don't make it clear why.
Without other information, the first thing to try is loosen the mounting bolts, reset the pistons, and re-adjust the caliper mounting with the rotor centered between the pistons in their fully reset state. Then actuate the brake a few times and make whatever small correction is needed to dial the centering in. That's how it works when things go right and there's no positioning issue weirdness happening.
If the caliper was moved over this far because it was the only way to get the inboard pad to clear the rotor, that will make the outboard piston live its life fully extended and the inboard one almost not extended at all. Having so much asymmetry tends to make the pads wear unevenly and can cause other issues with the piston function down the line, in addition to making the brake frustrating to adjust. Luckily, rotor shims are able to solve that problem. In an extreme case you can also just use M5 washers when you actually need that much thickness, but it's important they're all the same.