Try each of the following steps in order until the error is resolved:
  1. Export the file to a different format, such as .csv
  2. Recreate the report:
    1. Create a new report using the same parameters defined in the existing report
    2. Save the report parameters with a new name
    3. If the new report runs successfully, delete the old saved report

  3. Reboot the workstation
  4. Uninstall and reinstall Accounting for Nonprofits on the workstation