Insure that the data entered is complete and correct. This error will show if an email is submitted in an incorrect format, such as missing the @ symbol or missing a . for .com, etc. Try making a test donation on your end to see if you can replicate it. If not, then it was probably user error. If you can also replicate the issue, then it could be due to a required field that is hidden.
  1. Go to Fundraising > Donation Management
  2. Select All Donation Forms
  3. Click Edit
  4. Click Design Donor Screens
  5. Next to Donation Form, click Edit
  6. Under the selected Data Elements (box on the right), highlight each field and click Save Order and Edit Selected
  7. Make sure that all required fields that show on the backend are visible on the frontend