Window.location.hash => "invalid page component: null" in console

My app is generating the “invalid page component: null” message when I use page anchors:

e.g.,

window.location.hash = ‘#Section6AdditionalResources’;

It works fine, but generates that message.

(Also getting the “swiper initEvents attach” messages multiple times.)

Is this a bug, or some setting? I’ve tried a number of configurations, including:

    {provide: APP_BASE_HREF, useValue: '/'},
    {provide: LocationStrategy, useClass: HashLocationStrategy}

The error message happens regardless of strategy. Any help would be appreciated.