message: Document(s) not found for class Person with id(s) 538cb175bda00c38d309d914. summary: When calling Person.find with an id or array of ids, each parameter must match a document in the database or this error will be raised. The search was for the id(s): 538cb175bda00c38d309d914 ... (1 total) and the following ids were not found: 538cb175bda00c38d309d914. resolution: Search for an id that is in the database or set the Mongoid.raise_not_found_error configuration option to false, which will cause nil to be returned instead of raising this error when searching for a single id, or only the matched documents when searching for multiples.