Just would like to put my experience in. Tried for over 3 hours to book. Tried a Canadian Visa, a NZ Debit Mastercard, and Paypal. Kept getting errors for all 3.
Mastercard did a manual override to approve (showed up as Fraud eventually because I was trying to put it through so many times), Airbnb kept showing that they were putting through the amount in smaller instalments, but what they were actually trying to put through to Mastercard was the full amount (that I didn't have in my account, but according to Mastercard the error wasn't showing insufficient funds, it was showing an error with the 3D secure process Airbnb was using). So that is at least one internal Airbnb error with showing the customer that they're going to pay an instalment today, when actually they try to authorize the full amount.
Trying to use Paypal kept giving me the error message that that method of payment wasn't an option and I'd have to use a credit or debit card
On the second attempt calling my Visa they confirmed again that there was no issue on their end, and this time the guy noted that he'd been receiving lots of phone calls about people trying to book on Airbnb. So additional evidence that Airbnb is full of **bleep** when they say it's not a problem on their end.
Based on suggestions above I tried logging out and back in, didn't work. I tried using the app, including paying with Apple Pay, didn't work.
Finally what worked was changing it to pay in local currency rather than in Canadian dollars (on my Canadian Visa - which a minute before wouldn't go through).
So if anyone else is having this issue and sees this message, try changing the currency to whatever the local currency is and that might solve the issue for you. Good luck (you'll need it, because Airbnb seem to not give a **bleep** that this is a recurrent issue)