The following steps should be taken to resolve this error:
  1. Verify the link being used is https://bbms.blackbaud.com/
  2. Confirm the site is not being blocked by firewall (see IP Addresses and hostnames for the Blackbaud Payment Service, Blackbaud Checkout (formerly Blackbaud Secure Payments) and Blackbaud Merchant Services)
  3. Clear browser cache or try a different browser