Hi, elenaki. Welcome to the PayPal Community! Not being able to update a card and also not being able to add a card is a definite concern! I hope the following information is helpful.
In general, actions like updating a card, removing a card, and adding a card are reviewed by PayPal's Security System, and it might take steps to block an action if it determines there's a potential problem.
To address this, you may need to contact Customer Service by phone or email (click Contact at the bottom of any page when you're logged on to call or email), but you can also get in touch via Facebook (click Send Message on https://www.facebook.com/paypal) or Twitter (send a DM to @AskPayPal).
It could be that your card issuer changed some things with your card account which is preventing PayPal from allowing an update or to re-add the card. Checking with your card issuer could clear that up.
Another possibility is that the card was added and removed too many times, and it's not possible to add the card again. I'm sorry for any inconvenience this may cause, but PayPal would have to ask you to use a different card if that's the case.
I hope this information is helpful. Thanks for being a part of the PayPal Community!
Sincerely,
Michael
PayPal_Michael
