I can't link the credit card.

[yunfeng]

"This card is linked to another PayPal account. Please remove the card from the other account or try a different payment method."

I can't link my credit card.

before I link my card, I have close the old account and remove the card for 4-6 days. But I still can't link it on the new account.

[kernowlass]

@yunfeng 

Have you added / removed it from another account more than 8 times previously?

Have you tried clearing your history/cache or using another browser or device?

Have you tried adding it on the website and not on the app?