SharePoint:The workbook that you selected cannot be opened.

Issue:

When you open document in the document library if you get this error message "The workbook that you selected cannot be opened.

The workbook may be in an unsupported file format, or it may be corrupt.
Would you like to try and open this file in Excel? "

Resolution:

1. From Administrative Tools, open the SharePoint Central Administration Web application.
2. On the Central Administration home page, click Application Management.
3. On the Application Management page, in the Office SharePoint Server 2007 Shared Services section, click Create or Configure this Farm's Shared Services.
4. On the Manage this Farm's Shared Services page, click SharedServices1 (Default). This is the Shared Services Provider (SSP) that you will configure.
5. On the Shared Services home page, in the Excel Services Settings section, click Trusted file locations.
6. On the Excel Services Trusted File Locations page, click Add Trusted File Location.
7. In the Address section, type the location and name of the SharePoint Office SharePoint Server 2007 document library that you want to add as a trusted file location in Excel Services. If the document library is stored in the Windows SharePoint Services 3.0 content database, ensure that Windows SharePoint Services 3.0 is selected as the Location Type.
8. In the External Data section, select the type of data connections that you will allow workbooks in this trusted file location to contain and click OK.