We are migrating all credit card information from a payment gateway to another.
During this migration, you will not be able to manage your credit cards.
You will still be able to perform payments, though.
EDIT 29/07/17 11:35 UTC: the migration will begin at 12h15pm UTC. During the migration and for a few hours after, credit cards management might not work
EDIT 29/07/17 13:10 UTC: the migration is over, we will continue to monitor payments for a few hours