In this thread a user is confused by the "SynapseHTTPError: 403 Client Error: Forbidden" message originating from S3. S3 sends this response because we have configured the bucket not to allow egress from the bucket's region. (The user is trying to download to their local machine.) A user might also get Access Denied if they lack DOWNLOAD permission to a Synapse entity. The Python client could clarify whether the Forbidden response is coming from Synapse or from the underlying data store. In the latter case they would know not to pursue obtaining permission and instead seek to understand the restrictions imposed by the data store.