Business Data Connectivity object not found

When trying to use a Business Connectivity Services to connect to a WCF Service by using External Content Type in an External Data column I received the following error:

Business Data Connectivity object not found. Administrators, see the server log for more information.

And associated log:

Exception thrown while switching entities in BusinessDataFieldEditor Microsoft.BusinessData.MetadataModel.MetadataObjectNotFoundException: Cannot find a Default MethodInstance of Type ‘SpecificFinder’ on Entity (External Content Type) with Name ‘<External Content Type>’ in Namespace ‘<site url>’.     at Microsoft.SharePoint.BusinessData.MetadataModel.EntityCommon.GetDefaultMethodInstance(IEntity this, MethodInstanceType type)     at Microsoft.SharePoint.BusinessData.MetadataModel.Static.Entity.GetDefaultSpecificFinderView()     at Microsoft.SharePoint.WebControls.BusinessDataFieldEditor.PopulateFieldLists(SPBusinessDataField bizDataField)     at Microsoft.SharePoint.WebControls.BusinessDataFieldEditor.EntityTypeChanged(Object sender, EventArgs e)

The error seemed to occur because I had only created a ‘Read List’ operation while a ‘Read Item’ operation was also required based on the information I found in this article about Implementing a SpecificFinder:

A SpecificFinder returns exactly one external item. This stereotype is used to read an item, given its identifier. For example, given a Customer business object, this stereotype can be used to obtain detailed customer information for a given customer ID.

External content types should have at least one SpecificFinder method instance that returns a single instance, given an identifier. If you do not define aSpecificFinder method instance for an external content type, it cannot have actions on it, cannot be searched or indexed, and cannot be used in any of the Business Connectivity Services presentation features, except with the Related List Web Part.

(Easy) Solution: Create a ‘Read Item’ operation by following the steps in Connecting to a WCF Service Using Business Connectivity Services in Office 2010