Since Apple Pay Cash arrived, I have been unsuccessful activating the Cash card on my S1 watch. I thought I tried everything, including playing Stump the Genius at my local Apple Store (I won). Whenever I tried activating the card, the Watch app told me 2FA was required, but alas, 2FA was indeed enabled on my account. When I responded to upgrade to 2FA, it returned an error message to try again later. And so it went for a couple months. I tried removing the Cash Card, turning Apple Pay Cash off, upgrading watch and iPhone OS, even upgraded from 7+ to 8+, etc. Finally, last night, I decided to turn to the professionals, Apple Care. I started with a chat session via the iOS support app (Tier 1), who informed me I was doing everything right. She escalated to Account Security (Tier2) who similarly concurred. He escalated me to Watch team (Tier 3) and we found the solution, un-pair the watch from my iPhone, then re-pair it. My hesitation with jumping into this step (re-pairing) was a fear of losing all of the stuff I had configured on the watch. Turns out, when you re-pair the watch, you are prompted to restore from the existing settings, or set up as new. Alas, 20 minutes later, the pairing completed with all previous settings restored and Cash was able to activate in the watch app. I should have expected this, the Airport Utility does the same when you do a factory reset on a Base Station. Same for iOS devices. My only critique is they don't do a good job of letting us know they have our backs on these kinds of operations. Two lessons learned. Apple thinks about the little things when they design their software. Backup and restore are inherent in their products, despite no specific settings to enable this. I found very little documentation in searches of this, and Apple forums, so naturally, I was thinking it would be a destructive maneuver. Second, I don't have Apple Care on any of my devices, the S1 watch was past warranty, and the iPhone was in 1 year warranty, but not Apple Care extended. The Apple Care team, 3 layers of support and an hour of their time, was eager to help with no mention of asking for payment as most companies would. They were very personable as conversations turned to chit chat when waiting for operations to complete, no hesitation to engage in conversations into job satisfaction, and other off-topic things. The bottom line, Apple is unparalleled in how they value their customers. They put the nickel and dime stuff aside and will do what it takes to ensure success. This is why I continue to buy Apple products, and recommend them to others. It is a given glitches will happen, but the dedication to teaming up with you to find a solution is the key to satisfied customers. Bottom line: For anyone else having this issue, jump right into the re-pair solution, it works!