We sometimes get this error when trying to edit a feature service: "Error: Objects in this class cannot be updated outside an edit session [FeatureServiceName]." The data is in a SQL database and has been published to ArcGIS Server 10.7 (referenced, not copied.) The data is in a versioned dataset and has attachments.
Any ideas on what's happening? The other posts on this error seem to relate to programming errors.
Through a web map, a web app (Web AppBuilder), or Collector.