You are sharing a sync enabled web feature layer that includes data in a relationship class that uses the Object ID field as its primary key. Relationship classes using the Object ID field as its primary key are not supported in sync enabled web feature layers, this includes attachments based on an Object ID field. To use sync capability, relationship classes and attachments must be based on a Global ID field.
- Use Migrate Relationship Class to convert ObjectID-based relationship classes to GlobalID-based relationship classes.
- Disable attachments, Add Global IDs to the dataset, and Enable attachments. As long as a Global ID field is present, Global IDs will be used for the attachment relationship.
- Remove the data participating in the relationship class from the map.