Appears that the UI is incorrectly posting a String representation of the intended DTO.
- Create a Staging Profile
- from System -> Capabilities -> Create Capability select the "Yum: Staging Generate Metadata Capability"
- select the new Staging Profile
- possibly intentional, possibly bad UX, but you must enable this Capability in order to save it
- observe that the request is rejected and the error message shown by field validation indicates that it cannot recognize the repoId being passed: "Staging Profile '[object Object]' could not be found"
Same problem occurs for "Yum: Staging Merge Metadata" capability definition.