Scenario
The error is occurred when the balance sheet Report and row are no longer valid, because the layout containing theme has changed. To resolve this, we need to edit this reference row to re-select Report and Row.

Solution
- Go to financial Report Builder Page by clicking on the customisation Button in the Report.
- Then error message pop up on the top of the page.

- Click on the Edit Layout Button.
- Expand the row which has marked error icon (Retained Earnings). Check that the Net Income (Balance forwarded beginning of the Year) and net Income has warning error.

- Select the Net income (Balance forwarded beginning of the Year) row list
- Notice that the Row field is blank. Select Net income on this field.
- Click save.