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.
How are you trying to edit the feature?
Through a web map, a web app (Web AppBuilder), or Collector.