I also noticed this problem today. I had received my notice of my current PayPal Cashback Mastercard statement yesterday and went to set up the next monthly payment, but I discovered that the Credit Balance window and the link button to the card account (serviced by Synchrony) have both disappeared completely. I have received no notification of any issues with my account, the most recent communication I received was (as noted) my routine new-statement alert with current balance and minimum payment due. I think (I hope!) this is a technical glitch on their end; even if my account had been closed or limited for some reason, they would still have to send me notification via email (since this is now a paperless account) and there should still be a link to make payments on my outstanding balance.
P.S. I forgot to add that my PayPal Mastercard has also disappeared from my wallet. @shnback - did your own card mysteriously disappear from your wallet, too?
P.P.S. Upon further research, a lot of other people have been reporting this issue since yesterday. It appears that the problem is actually on the issuer end (Synchrony Bank) and that the issue is affecting other cards issued by Synchrony. You might need to contact Synchrony directly rather than try to go through PayPal.
