AGOL toggle on "Enable Attachments" in hosted feature layer polygon layer results in error message

Question

I'm working with a hosted feature layer polygon layer in ArcGIS Online.  When I try to toggle "Enable Attachments" to ON I get this error message:

I have other similar layers that have no problem toggling "Enabling Attachments" on or off. I cannot figure out what is different about this layer.  I'm checking all of my settings and they appear to be the same as other layers that allow me enable attachments.  Any ideas why this layer won't allow me enable attachments?

KansasDASC · Answer

I have suspected that part of the issue, which might explain why republishing or trying a brand new FL works, is that after we publish the FL, we use the Python API to make changes to the service definition so that certain capabilities are always on or off, and not the defaults. We also create a number of field domains. I don't know if these SD changes impact the attachments toggle?

LindseyGreidanus · Answer

I just had this issue as well, following the steps describe here to create an independent copy of a feature layer in AGOL.

The page does mention that related tables will not work, which is what the attachments on a feature layer is based on.

I got the same error updating layer warning when I tried to enable attachments, but when I had a call with ESRI support we were not able to replicate the issue on a fresh feature layer. I tried replicating it again after the call with the settings changed from the default and that seems to be what caused the issue - I got the error message again.

The recommended work-around was to save the layer as a FGDB and then republish it again from Pro.

KansasDASC · Answer

@ShaneONeill_144 @KimT @tfield  Any update on this. I seem to have discovered that it's affecting our workflow to update a AGO hosted feature layer and related tables. I have published the same GDB as a FL in a different folder and can toggle attachments, but the one I'm working on can not. The error I get is "Unable to update feature service layer definition."

We are making updates to the FL through the API for Python. In the code we are making changes to the service definition to make sure that after each overwrite, the layers are still Sync-enabled, Edit-enabled, and select capabilities. Without updating the SD, these options revert and we have to change them manually, hence the code.

When I try to update the SD in the code with something like:

TABLE.manager.update_definition({"hasAttachments": True})

I just get this error: "Unable to update feature service layer definition. There are no primary or candidate keys in the referenced table..."