Unable to Load Workbook + The workbook that you selected cannot be opened + The workbook may be in an unsupported file format, or it may be corrupt

Excel services work with Excel 2007 and allows you to share, load, calculate Excel workbooks on Microsoft SharePoint Server 2007 portals and dashboards. You can share an entire Workbook or just few parts of it like charts, tables etc. By using a Web browser, end users can view and interact with the workbooks.

However, at times, when you publish a workbook to Excel Services and try to load it in a browser, you might run into an error message

Unable to Load Workbook

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?

How I resolved this issue:

1)   Remove the space character that is in front of the caret operator in the formula.

2)   Save the workbook in the non-XML binary workbook format (.xlsb). Then, publish the workbook to the server

If you have any queries/questions regarding the above mentioned information then please let me know. I would be more than happy to help you as well as resolves your issues, thank u.

For more information about Excel Services, visit the following Microsoft Web sites:

1)   http://msdn2.microsoft.com/en-us/library/ms546696.aspx  

2)   http://office.microsoft.com/en-us/sharepointserver/HA101054761033.aspx