Sharing a feature layer as a copy through a collaboration (or creating a new feature service from a URL) fails if a layer in the feature service has more than one relationship with the same Origin Primary Key field.

Workaround

Replace the relationship in ArcGIS Pro and point to a different field than the field used in the other relationship set for the other feature layer. This stops the error from occurring when working with the layer in ArcGIS Online. The workaround requires the data to be republished or overwritten.

Alternative work around. When adding the service URL in the new item workflow use the URL specific path, instead of the feature layer (URL) path. The URL option will allow the data to be created as expected.

Steps to Reproduce