Unable to Add Phone Number to Microsoft Account

Question

For the past 8 months, attempts to add a phone number to my Microsoft account have been unsuccessful. This usually occurs when trying to redeem gift cards, and the process consistently results in the following message: "There's a temporary problem with the service. Please try again. If you continue to get this message, try again later."

Answer 1

Disable "Passwordless account":

https://account.live.com/proofs/manage/additional