PayPal will be performing maintenance on June 23, 2016 from 10:00 PM PDT to 10:10 PM PDT (June 24, 2016, 12:00 AM – 12:10 AM CDT). During this window, merchants may receive an error when processing transactions. Merchants are encouraged to retry transactions after the maintenance window is complete.
Please see PayPal’s status blog for more information.