You are attempting to add a record to a person who is designated as read-only. No changes can be made to Josephine Sarah Marcus LDSW-2ZV. Here is a link to more information about read-only persons.
Thank you for posting a question in Community. The reason you see the error message in source linker is because Josephine Sm Marcus LDSW-2ZV is a "Read Only" record. With these types of records, no additions or changes can be made by guests, including detaching an incorrectly linked source.