You are sharing a map image layer that contains a topology and the subtype field is not editable. When sharing a topology layer, the subtype field must be editable for all topology layers.
Ensure that the subtype field is editable for the layer:
- Hover over the analyzer message. Click the Options button that appears and click Select Layer In The Contents Pane. The layer with the subtype field hidden is selected.
- On the ribbon, under Feature Layer, click the Data tab. In the Design group, click Fields .
- In the fields view, uncheck the box in the Read Only column for the subtype field to make the field editable. Click Save .