Find Data Validation Errors
By Neale Blackwood
When using an in cell drop down via Data Validation it is possible to Paste Special an invalid value into the cell. Excel has a feature to track that type of validation error. Invalid entries can also occur if the list used for the in cell drop down has changed since the value was selected.
Excel 2003 and earlier:
Right click the toolbar and select the Formula Auditing toolbar. The two tools at the end of the toolbar are associated with the Validation errors. The first tool – Circle Invalid Data – circles in red any validations that don’t match the current Validation. The other tool clears the invalid circles.
In the Data tab of the Ribbon in the Data Tools section the drop down for Data Validation has the Circle Invalid Data and Clear Validation Circles options.