Application Error : Invalid Session

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What causes this Error “Application Error : Invalid Session”

I receive this error when using samples from the Wisej site and in my own test applications.

I am using a  VS2015 and a Trial license of Wisej runtime version 4.0.30319

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First off, thanks for all the help on this issue.

I believe I figured out the problem and it wasn’t WiseJ related.

I had a diagnostic log being written to the \bin folder.  Every time this log was written to, because it is in the bin folder, the application thinks that it needs to reset the application.  This would invalidate the session.

Once I stopped writing to the diagnostic log, the invalid session issue went away.

I thought I would post the “fix” in case anyone else made the same mistake that I did.


  • Luca (ITG)
    Thank you for the update. Good to know, I though it was only changes to Web.config that made IIS reload.
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Note: I am using “cookieless”: true in my .Json file

Does it work if you refresh” YES and the sid changed, Then you get the error right away? NO after about 5 minutes

Added validateClient: false, the error still occurs after about 5 minutes. Then I removed the Application.SessionTimeout += Application_SessionTimeout handler from Program and  all worked fine for at least an hour.


Thank you for your help Luca, I’ll keep testing it.


  • Luca (ITG)
    If the sid changes when you hit refresh it means that wisej is unable to retrieve the session id (sid) or the client validation fails. I tried cookieless and to add the handler but it always works. What I don’t understand is what do you mean you get the error after 5 minutes? Is it 5 minutes of inactivity?
  • Alex Berze
    Sorry for the delay Luca I was having to much fun play with Wisej. Yes it was 5 minutes of inactivity.
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It means that the app is trying to access a session that expired. Does it work if you refresh and then you get the error right away?

Try to add “validateClient”: false to Default.json and let me know if the problem is still there. Also let me know the Wisej version you are using.


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