In SharePoint 2013, the App Pool that is running the Access Services web service needs to have the property "Load User Profile" set to True in IIS configuration for access services to function correctly.
White Paper Reference: http://www.microsoft.com/en-gb/download/details.aspx?id=30445
White Paper Reference: http://www.microsoft.com/en-gb/download/details.aspx?id=30445
