Consider the following scenario:
You have a server that is running Microsoft SharePoint Server 2010 together with Enterprise client access license (CAL).
You create an external list that is based on a Business Connectivity Services (BCS) Simple Solution.
You take the external list offline to Microsoft Outlook.
You change the external list on the server that is running SharePoint 2010.
In this scenario, when you try to synchronize the changes that were made to the external list, you receive the following error message:
The shim execution failed unexpectedly - Server was unable to process request.
Incompatible field type for one of the expressions in the query.
This issue occurs because, when you take the external list offline to Outlook, the subscription file that is created uses a filter that has as a value. This value is the parameter name that is used by the solution. By default, the filter value should be NULL. When the parameter name is used as a value, the synchronization fails.