Layer fails to load and returns the error message, "21 Invalid JSON" when a field with a range domain that is included in a subtype is excluded from the view definition in ArcGIS Field Maps (iOS).

Workaround

1. Include the field in the view definition that has the domain applied that is used in the subtype.
2. Remove the domain from the subtype in ArcGIS Pro and republish the hosted feature layer and recreate the view.

Steps to Reproduce