When trying to open a sample workbook using SharePoint Excel Services I got a nasty error:

You do not have permissions to open this file on Excel Services.

Make sure that the file is in an Excel Services trusted location and that you have access to the file.

Access Denied Message

In my case I had an Excel workbook in a ReportLibrary on my site.  And yes I had added the library to the SSP Trusted File locations using Central Administration.  Took me a bit of tinkering to figure out what was going on….

The URL to my ReportLibrary that contained the Excel spreadsheet was:  “http://sharepoint/Reports/ReportLibrary/Forms/current.aspx”

So I used this as the Trusted File Location.  Turns out that SharePoint doesn’t want the “/Forms/current.aspx” part of the URL identifying the Windows SharePoint Services Location….. AND the other trick is that the “Windows SharePoint Services” location has to end with a “/“.  So the URL I needed to use for the Trusted File Location is:  “http://sharepoint/Reports/ReportLibrary/”

Windows SharePoint Service Location ends with a "/"

Hope this helps to keep others out there from pulling there hair out and cursing SharePoint!!