My Clipper Card failed on my Apple Watch over the weekend when trying to get on BART and Muni (it had been activated and used once before to confirm it worked), so I ended up having to buy a new physical Clipper Card. After talking with Clipper Card support today (after a 30 minute wait) they convinced me to delete the Clipper Card from the Apple Watch Wallet. After deleting the Clipper Card, I was unable to get it re-activated immediately. Thanks, Nicole, for the suggestion. I was able to get it successfully re-activated on my Apple Watch after waiting about four hours. Now, hopefully, it will work going forward, otherwise this may be failed a "experiment" on the part of Clipper Card and/or Apple. If it fails again, I'm considering reporting the card as "lost" and getting a new physical card...arghh...