I booked a hotel in Singapore using booking.com. It's a no cancellation booking. I payed it by using a Visa debit card. Booking was complete. But after 1/2 hour booking.com sent me an email that my credit card is invalid and ask me to update the card before 24 hours. I used a debit card. Not a credit card. Is booking.com accepts debit cards? If not, why I receive these emails? What will be next? I have no idea about it. If you can help me it's so valuable.
Ask your bank, because they are the ones that declined the charge.
Not all debit cards are authorized for online use, such as the ones my bank gives. So just because it looks like a credit card, it may not be authorized for online transactions.
Bottom line, check with your bank as they are the only ones with a definitive answer.
It looks from the screen shot as though they gave you a check list of possible causes. Unless that lists using a debit card rather than a credit card as a cause, forget that as the issue.
After the obvious issues such as mistyped number or lack of funds, card security checks can be an issue. I have encountered that as a problem when preparing for international vacation travel. If so, it can probably be fixed by calling the service number on your card, identifying yourself, and stating that you are planning travel to Singapore and are booking a hotel room.
It's most likely your bank blocking the transaction. I had the same issue at Booking.com, had enough funds on my debit and yet was told it was "invalid." I called my bank and surely enough they had blocked the transaction without even letting me know. I didn't receive a text or a call asking to verify if I was the one making the payment, they just blocked it.
How ridiculous that the client has to contact the provider every time they decide to block a transaction involving a few $100s. Some much emphasis on fraud prevention they forget about the customer. Anyways, next time just call your bank to approve the transaction whenever you get an "invalid card" issue.