后台访问 栏目管理 出现以下错误是怎么回事？
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 type 'PageAdmin.lanmu_1' is ambiguous: it could come from assembly 'D:\admiweb\bin\PageAdmin.Lanmu.DLL' or from assembly 'D:\admiweb\bin\PageAdmin.Master.DLL'. Please specify the assembly explicitly in the type name.
Source Error:
Line 1: <% @ Page Language="C#" Inherits="PageAdmin.lanmu_1" %>
Line 2: <% @ Register TagPrefix="aspcn" TagName="uc_head" src="head.ascx" %>
Line 3: <aspcn:uc_head runat="server" Type="lanmu_1" />
Source File: /master/lanmu_1.aspx Line: 1
--------------------------------------------------------------------------------
Version Information: Microsoft .NET Framework Version:2.0.50727.832; ASP.NET Version:2.0.50727.832