PowerPivot – “Data overflow converting to the data type for table ‘68868d91-787b-49fa-bb65-fa1cc475c3c8’ column ‘Tape_Date’.”

If you’re trying to open a workbook from the SharePoint 2010 PowerPivot Gallery and you get this error: Data overflow converting to the data type for table ‘xxxxxxxxxxxxx’ column ‘Tape_Date’.” 

This is Excel Services saying that the PowerPivot Workbook  is above the maximum Excel Workbook file size as configured in Excel Services. Solution:

1. Go to Central Administration
2. Application Management
3. Manage service applications
4. Excel Services Application
5. Trusted File Locations, and select the reports library or document library your web part is calling or where the files are
6. Workbook Properties –> reconfigure “Maximum Workbook Size” to larger than the PowerPivot Workbook in question

Return to the PowerPivot Gallery and the Workbook should open as expected.