When editing a Page Layout in Visual Studio 2010 the 'asp' prefix is not recognized.
For example:
<asp:Content contentplaceholderid="PlaceHolderBreadCrumb" runat="server">
Has 'asp' green-underlined stating "Unrecognized tag prefix or device filter 'asp'".
Among other annoyances, there's no intellisense for controls, no auto format of code, etc.
I already "forced" the editor to use "Web Form Editor", but still doesn't work. These are my references:
<%@ Assembly Name="Microsoft.Web.CommandUI, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
<%@ Page Language="C#" Inherits="Microsoft.SharePoint.Publishing.PublishingLayoutPage,Microsoft.SharePoint.Publishing,Version=14.0.0.0,Culture=neutral,PublicKeyToken=71e9bce111e9429c" %>
<%@ Register TagPrefix="asp" Namespace="System.Web.UI" Assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" %>
<%@ Register TagPrefix="SharePointWebControls" Namespace="Microsoft.SharePoint.WebControls" Assembly="Microsoft.SharePoint, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
<%@ Register TagPrefix="PublishingWebControls" Namespace="Microsoft.SharePoint.Publishing.WebControls" Assembly="Microsoft.SharePoint.Publishing, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
<%@ Register TagPrefix="CustomTag_0" Namespace="Microsoft.Office.Server.WebControls.FieldTypes" Assembly="Microsoft.Office.Server.UserProfiles, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
<%@ Register TagPrefix="CustomTag_1" Namespace="Northridge.SharePoint.Common" Assembly="Northridge.SP2010.Common, Version=1.0.0.0, Culture=neutral, PublicKeyToken=82b873716895b724" %>
<%@ Register TagPrefix="WebPartPages" Namespace="Microsoft.SharePoint.WebPartPages" Assembly="Microsoft.SharePoint, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>