ASP.NET session has expired

ASP.NET session has expired          说明: 执行当前 Web 请求期间，出现未处理的异常。请检查堆栈跟踪信息，以了解有关该错误以及代码中导致错误的出处的详细信息。            

异常详细信息: Microsoft.Reporting.WebForms.AspNetSessionExpiredException: ASP.NET session has expired

 

网上的回答：

There is a known bug with the viewer in when ASP.Net is set to use cookieless sessions.

The problem is most likely that you are using in-proc session state (the default).  When you use in-proc session and have two worker processes, each one has its own independent version of session.  As a result, if a request for the aspx page is routed to one worker process, but the request for the report content goes to the other process, the second request will not find a session and assume it has expired, generated the error you see.  The two ways to work around this are to either use only a single worker process or to use out-of-proc session state, such as SQL Server.  See this article for more details:

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我是将应用程序池的模式由经典改成集成解决。。。