Error in the shaman saying that the type was not found

Question

In my shampoo I have:

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:local="clr-namespace:Opa"   
             xmlns:maps="clr-namespace:Xamarin.Forms.Maps;assembly=Xamarin.Forms.Maps"  
             x:Class="Opa.MainPage">

    <maps:Map MapType="Street" />
...

</ContentPage>

maps:Map type not found. Check if there is no map Missing Assembly reference and if all assemblies referenced were created.

But note that it is declared in the Contentpage header on that line:

xmlns:maps="clr-namespace:Xamarin.Forms.Maps;assembly=Xamarin.Forms.Maps"

Why the mistake?

Edit1

My project is called Ola

So is my headline

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:local="clr-namespace:Ola"   
             xmlns:maps="clr-namespace:Xamarin.Forms.Maps;assembly=Xamarin.Forms"  
             x:Class="Ola.MainPage">

    <maps:Map MapType="Street" />

Answer 1

You are reversing things, assembly is the name of the dll and usually has the same name as your project, if the one in question is called only Xamarin the Assembly is just Xamarin and not Xamarin.Forms.Maps which would be the path with the namespace of the class that represents the maps control. But probably the name of your project should be Xamarin.Forms

 xmlns:maps="clr-namespace:Xamarin.Forms.Maps;assembly=Xamarin.Forms"