In Microsoft SharePoint Designer 2010, you change the LobSystem properties by editing the Connection Properties of an External Content Type, and you change the endpoint for the LobSystem. In Operations Design view, you try to add a new method to the External Content Type. When you do this, you receive the following error message:
The system definition with the same name as this data source already exists in the Business Data Connectivity Metadata Store and it refers to a different data source. Cannot complete operation generation. Add a connection to this data source with a different name and try again.
This issue occurs because the External Content Type Designer of SharePoint Designer 2010 does not change the discovery LobSystem when changes are made to the External Content Type Designer’s corresponding LobSystem. When you edit the Connection Properties of an External Content Type, the edit changes the actual LobSystem. But the edit does not change the discovery LobSystem. Therefore, when you add a new method to this External Content Type, the DataSource cannot be resolved correctly.
Note The discovery LobSystem is a LobSystem that has the Discovery Property, and this discovery LobSystem is used only by SharePoint Designer 2010.
To work around this issue, use one of the following methods:
Re-edit an existing Operation before you add a new Operation ion the External Content Type in SharePoint Designer 2010.
Delete the DataSource in the Data Source Explorer, and then re-discover it.
Delete the DataSource in the Data Source Explorer, and then re-edit any of the methods. When you do this, the DataSource is automatically discovered.