Assume that you try to implement a search across multiple fields by using the Access Services in Microsoft SharePoint Server 2010 or in Microsoft SharePoint Foundation 2010. When you try to create a query an expression based on user-defined parameters, Access Services cannot process the request and you receive the following error message in the Unified Logging Service (ULS) log:
Critical There was an error in communicating with Access Database Service Access Database Service URL exception: The underlying connection was closed: A connection that was expected to be kept alive was closed by the server.
To resolve this issue, apply the following updates:
2276338 Description of the SharePoint Server 2010 hotfix package (osrchwfe-x-none.msp): August 31, 2010
2266423 Description of the SharePoint Foundation 2010 hotfix package (Sts-x-none.msp): August 31, 2010
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.