I'm sorry, but the knowledge sources provided do not contain any information about the specific error message:

Error: Source freshness for invocation id effb4596-477e-45cd-8d93-2405e95b4783 were already uploaded.

after upgrading Elementary Data from version 0.16.1 to 0.20.0. There are several discussions about issues with source freshness uploads, version compatibility, and related bugs, but none mention this exact error or provide a solution for it. If you need further assistance, I recommend opening an issue on the [Elementary GitHub repository](https://github.com/elementary-data/elementary/issues) or reaching out in the Elementary Slack community, providing details about your workflow and the error context. If you have additional logs or context, sharing those may help the community or support team diagnose the issue more effectively.