I'm attempting to create a SharePoint workflow that creates a new item in an external list using the "Create item in [External List Name]" action available in SharePoint Designer.
Currently, I keep getting an error that states "The workflow could not create the item in the external data source. Make sure the user has permissions to access the external data source and create items." The associated User ID is the "System Account" (SHAREPOINT\system).
From some research I did, I was led to believe that the workflow uses the SP Webapp account whenever it creates a new item in an external list. As described at How to authenticate BDC to the external system?, I granted SP Webapp object permissions and metadata store permissions in the External Content Type and in the External System. I also granted it permissions on the external list and the SQL Server of the external list. This didn't work for me, though.
At one point, I changed the default SSS from my "Partitioned Secure Store Service Application" to a custom one that I created. This worked, but it also broke a few other systems on my organization's SharePoint, so I had to revert back to the Partitioned SSS. I would like to create a new target application on the Partioned SSS, but, due to the partitioning, I cannot do this. Is there a way to have my External System use the target application on my custom SSS even though it is no longer the default SSS?
Are there any other potential solutions that I may be overlooking?