Can't use pagelayout, error Unknown server tag 'PublishingNavigation:PortalSiteMapDataSource'.

Coordinator
Nov 27, 2014 at 1:11 AM
It sounds as though the tag, PublishingNavigation, has not been registered properly at the top of the HTML Master page or HTML Page Layouts.

Try adding the following to your HTML page layout and/or HTML master page
<!--SPM:<%@ Register Tagprefix="PublishingNavigation" Namespace="Microsoft.SharePoint.Publishing.Navigation" Assembly="Microsoft.SharePoint.Publishing, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>-->
Eric
Coordinator
Dec 2, 2014 at 4:34 AM
That is very interesting, I reviewed the codebase at it does appear as though the page layouts are missing the proper registration tag as I specified below yet my demo site is working without it. I have not seen that before, if a prefix tag such as PublishingNavigation is used but not registered, it should not be working. I will get this updated in the project assets.

It does not matter too much where the registration tag is added to the HTML Page Layout as long as it is within a ContentPlaceHolder , i.e., within a block such as:
<!--MS:<asp:ContentPlaceHolder ID="PlaceHolderLeftNavBar" runat="server">-->
<!--ME:</asp:ContentPlaceHolder>-->