1. Open the column in the Income Statement
2. Delete the heading
3. Re-enter the heading
4. Click Save and Close
5. Save the report parameters
6. Click Preview

If you still experience the issue:
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.

Note: If you mark the checkbox to Apply a Color Scheme under Color Scheme on the Format tab, the column headers will not be underlined.