装完pageadmin主页显示没有问题，接下来装的dz nt，修改好文件上传，输入安装路径在打开网页，主页也显示错误了，见下：
Server Error in '/' Application.
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Configuration Error
Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.
Parser Error Message: The entry 'HttpModule' has already been added.
Source Error:
Line 18: <httpModules>
Line 19: <add type="PageAdmin.UrlReWriteModule" name="HttpModule" />
Line 20: <add type="Discuz.Forum.HttpModule, Discuz.Forum" name="HttpModule" />
Line 21: </httpModules>
Line 22:
Source File: f:\wwwroot\xxxxxxxx\wwwroot\web.config Line: 20