Commented Unassigned: Element 'ScriptManager' is not a known element [27908]

Hi,
I updated the AjaxControlToolKit, but now I have this Issue.

in my web Config I have this:
<pages>
<controls>
<add tagPrefix="ajaxToolkit" assembly="AjaxControlToolkit" namespace="AjaxControlToolkit" />
</controls>
</pages>

I found this:
<add tagPrefix="ajax" namespace="System.Web.UI" assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>

Whit that change 'ScriptManager' work fine, but doesn´t work ControlBundles
<ControlBundles>
<AspAjax:ControlBundle Name="FilteredTextBox" />
<AspAjax:ControlBundle Name="ModalPopup" />
<AspAjax:ControlBundle Name="Calendar" />
</ControlBundles>


I Used Nuget, I need to do someting else?
Comments: Check out the v15.1 [migration gide](https://ajaxcontroltoolkit.codeplex.com/wikipage?title=Upgrade%20your%20project%20to%20AjaxControlToolkit%20v15.1&referringTitle=Documentation) (step 4)   If you use named Control Bundles (defined in the ~/AjaxControlToolkit.config file), then adjust the script bundle virtual path as shown below:  "~/Scripts/AjaxControlToolkit/<ControlBundleName>Bundle".