Same here, I've had no problem in the past doing updates in the past on my 15 CVO Limited or my current 17 CVO Limited, and my bike took the 1.21.2.1 update just fine. I also noticed the new dealer update and figured why not.. And, I ended up in the same loop that wouldn't update. I tried to download the file again, no luck. Reformatted the stick FAT instead of FAT32, no dice. Finally I put the files for 1.21.2.1 back on the stick and the infotainment grabbed those and reinstalled 1.21.2.1. Of course I couldn't leave well enough alone since the dealer update didn't take, so I tried again, and again I ended up in the loop. I threw the infotainment files back on the stick and it did another update to 1.21.2.1 to get out of the loop and now i'm going to leave it as is, for now at least.