All MongoMapper exceptions inherit from MongoMapper::Error, which inherits from Ruby’s StandardError.
- MongoMapper::DocumentNotFound: Raised when document expected to exist, but not found in database (ie: find!).
- MongoMapper::InvalidScheme: Raised when connecting using URI with incorrect scheme.
- MongoMapper::NotSupported: Raised when trying to do something not supported, mostly with embedded documents.
- MongoMapper::DocumentNotValid: Raised when creating, updating or saving with ! and a document is not valid.
- MongoMapper::AccessibleOrProtected: Raised when attr_accessible and attr_protected are both called on the same model.