1. If 'StaffViewsComponent' is an Angular component, then verify that it is part of this module. 2. To allow any element add 'NO_ERRORS_SCHEMA' to the '@NgModule.schemas' of this component. code example

Example: add 'no_errors_schema' to the '@ngmodule.schemas'

schemas: [
    CUSTOM_ELEMENTS_SCHEMA,
    NO_ERRORS_SCHEMA
  ]