XSD schema does not specify a target namespace when declaring the type element

Validator error: Error resolving component 'ConfigType'. It was detected that 'ConfigType' has no namespace, but components with no target namespace are not referenceable from schema document 'null'. If 'ConfigType' is intended to have a namespace, perhaps a prefix needs to be provided. If it is intended that 'ConfigType' has no namespace, then an 'import' without a "namespace" attribute should be added to 'null'.