Suitable constructor for type not found (View Component)

Solution 1:

The problem is that your constructor is private:

private WidgetViewComponent(IWidgetService widgetService)
{
    _WidgetService = widgetService;
}

It should be public otherwise the DI cannot access it:

public WidgetViewComponent(IWidgetService widgetService)
{
    _WidgetService = widgetService;
}