What should I do when a credit card shows error disabled?

If you are certain that the card is actually valid and you have reviewed the history (see above), you can edit and enable the card for auto processing. 

Note that you risk your gateway (Moneris, Elavon etc) blocking this card for you if you have too many Declines without an approval for the card.  See more in the section below.

If you are not sure that the card is still good, review the transaction history by clicking the clock icon and then the result pill to see the detailed transaction messages.  They will generally give you a good idea on what happened.  See above.

You will very likely need to request a new card from your customer using credit card icon on the error disabled profile.

You will then see a window that allows you to send your customer a Payment Info Request to replace the problematic card.  Send your customer the Payment Info request and when they fill out the request, the profile will be re-enabled and be ready for Auto Processing.