Server Error in '/' Application.

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: The file '/masters/MasterPage3.master' does not exist.
Source Error:
Line 1: <%@ page title="" language="C#" masterpagefile="~/masters/MasterPage3.master" autoeventwireup="true" inherits="_Default, App_Web_dfkx1zk5" enableviewstate="false" %>
Line 2: <%@ Register src="controls/mainpage/divpublisher.ascx" tagname="divpublisher" tagprefix="uc1" %>
Line 3: <%@ Register src="controls/mainpage/divclass.ascx" tagname="divclass" tagprefix="uc2" %>
Source File: /Default.aspx Line: 1
Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.1025