Dear Sir
Thanks for your reply, I try to start ASP.NET State Service and add sessionState mode="StateServer" cookieless="false" timeout="100" in web.config
, and than the problem seems to be solve

Is it a right way to solve this problem?
I deploy this web application in three servers, only one server has this problem, what is the root cause in this problem ?
Would you please help me to understand and solve this problem?
Thanks a lot.
          
Best Regards,
Charles MF

Hi,

Does this happen with all web browsers or with a particular one?

Is the session state enabled in the Web.config file?

Best Regards,
Nevron Support Team

When my asp .net  create a chart url like http://localhost/Report/NevronChart.axd?InstanceGuid=xxxxxxxxxxxx&SnapshotGuid=xxxxxxxxxxxx

Sometimes, I can not see chart on browser but ,after i do refresh on browser , the chart could show on browser . I don't understand what's happen, I need help.

Best Regards,