Enabling identifiers to be updated requires a 'PreUpdaterField' to be configured on the corresponding Update operation. This ...

Enabling identifiers to be updated requires a 'PreUpdaterField' to be configured on the corresponding Update operation. This is not supported by SharePoint Designer. If you need this functionality edit the external content type outside of SharePoint Designer. For more information see the documentation for 'PreUpdaterField' available at msdn.microsoft.com