CS0030: Cannot convert type 'MasterPage' to 'ASP.masterpage_master'

Question

Anybody know how to start trying to figure this error out? This is the only error I get when debugging the app. I get no errors during the compile phase. This is an ASP.NET 3.5 App. Breaking on my local machine and a server.

Line 149:        public new ASP.masterpage_master Master {
Line 150:            get {
Line 151:                return ((ASP.masterpage_master)(base.Master));
Line 152:            }
Line 153:        }

Source File: c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\root\e04eaf87\eb3a5588\App_Web_tmdefault.aspx.cdcab7d2.ytin7a8n.0.cs    Line: 151 

On the Server I get this error:
Parser Error
Description: An error occurred during the parsing of a resource required to service this request. Please review the following specific parse error details and modify your source file appropriately.

Parser Error Message: Could not load type 'Default'.
Source Error:
Line 1: <%@ Page Language="C#" MasterPageFile="~/MasterPage.master" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="Default" Debug="true"%>
Line 2: <%@ MasterType virtualPath="~/MasterPage.master"%>
Line 3:

Answer 1

Have you installed SP1 for the .NET Framework? There is a known issue in pre-SP1 that was similar to this.

Answer 2

Sounds like the problem would relate to http://stackoverflow.com/questions/1998931/how-to-fix-namespace-problem-with-autogenerated-master-property-if-mastertype-is. Still unresolved