Session Timeouts Causes and Remedies

Causes for Session Timeout could vary from-

1. Modification in Machine.Config, Web.Config or Global.asax files
2. Application's bin directory or its contents modified 
3. Antivirus is running on the  .config /.aspx files
4. The number of re-compilations (aspx, ascx or asax) exceeds the limit specified by the <compilation numRecompilesBeforeAppRestart=/> setting in machine.config or web.config  (by default this is set to 15) 
5. The physical path of the virtual directory is modified 
6. The CAS policy is modified
7. Sub-Directories of Application are deleted or renamed

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