Verify that the correct credentials are being entered:
At Configuration > General in the Supervisor account: enter Blackbaud Payment Service (BBPS) user name and password

At Configuration > Business Rules > Merchant Accounts: enter Blackbaud Merchant Services (BBMS) user name and password

If the BBPS credentials are verified as correct, refer to following to troubleshoot the error message: Error: The Raiser's Edge cannot connect to the Blackbaud Payment Service

If you need to reset the user name and/or password for Blackbaud Merchant Services or Blackbaud Payment Service, refer to the following: How do I change my Blackbaud Payment Service (BBPS) or Blackbaud Merchant Services (BBMS) password.