Issue Description :
While creating BCS connection through SP2013 designer using BCS service application from SP2016/19 Publishing farm to SP2013 consuming farm you might get below error message.
Cause:
This is a known issue when consuming a published BCS service application from a SharePoint 2016/19 farm in a SharePoint 2013 farm. When communicating with the SharePoint 2013 farm, the SharePoint 2016/19 BCS service app looks for the 16.0.0.0 version of the “Microsoft.BusinessData” assembly, which does not exist on a SharePoint 2013 farm. Instead, SharePoint 2013 has the 15.0.0.0 version of the assembly.
Resolution\Workaround:
To resolve the issue, we need to add a redirect for the “Microsoft.BusinessData” assembly to the web.config of any web applications in the SharePoint 2013 farm that will be utilizing the connection to the SharePoint 2016/19 BCS service application. This entry needs to be added to the web.config for the web applications on every server with the “Microsoft SharePoint Foundation Web Application” service running.
1. Navigate to C:\inetpub\wwwroot\wss\VirtualDirectories\<portNumber>
2. Make a backup copy of the web.config file
3. Edit the web.config file
4. Within the <runtime>, locate the section called <assemblyBinding> (search for the closing </assemblyBinding>)
5. Just before the closing </assemblyBinding>, add the following lines to the web.config file <dependentAssembly xmlns="urn:schemas-microsoft-com:asm.v1"> <assemblyIdentity name="Microsoft.BusinessData" publicKeyToken="71e9bce111e9429c" culture="neutral" /> <bindingRedirect oldVersion="16.0.0.0" newVersion="15.0.0.0" />
</dependentAssembly>
6. Save the web.config file
7. Perform IISRESET
8. Repeat steps on all WFE servers