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WCF CLIENT gets a "not found" error

    Question

  • My co-worker and I have been working together on a Silverlight application for a long time.  She has one part that is randomly failing when calling the WCF service.  By looking at the traffic, we can see that the ENTIRE result has been sent down from the server.  It IS quite large.  70,000+ records.  On her machine while running in VS 2013, it works fine.  But from the actual IIS remote server, the first time it may work, and the second time it may fail, but not always, but often.

    The entire result seems to be downloaded and the code from the service is 200, but a "not found" error is reported in the Completed event handler.  If I had to guess, I would guess that the deserializer ran into memory problems and its error handling makes it LOOK like a "not found" on the server, but it isn't really that.

    Also, when she runs it on her machine under VS, but hooks up to the remote database, it doesn't seem to ever have the problem.  Is it maybe some problem with IIS somehow?

    Anybody got any ideas how to figure out what is really happening and get around this more or less random error?

    (we are already handling SilverlightFaults on the server and getting server exception messages displayed when that happens)
    • Edited by Mark Tiede Wednesday, May 31, 2017 2:13 PM
    Wednesday, May 31, 2017 2:11 PM

All replies


  • Hi Mark Tiede,

    >>But from the actual IIS remote server, the first time it may work, and the second time it may fail, but not always, but often.

    From your description, It is difficult to analyze the specific reasons.

    You can use the F12 to open the Browser debugging tool to detect detailed error messages. You can show us the detailed error messages. This will help us quickly analyze your problem.

    Also, I suggest you can visit the IIS forums for getting help. From your description, your question is more related to IIS.

    IIS forums:


    Best Regards,

    Yohann Lu


    MSDN Community Support
    Please remember to click "Mark as Answer" the responses that resolved your issue, and to click "Unmark as Answer" if not. This can be beneficial to other community members reading this thread. If you have any compliments or complaints to MSDN Support, feel free to contact MSDNFSF@microsoft.com.

    Thursday, June 1, 2017 5:47 AM
  • Yohann, I wasn't looking for analysis of specific reasons. I was looking for any suggestions.

    IIS would not seem to be the appropriate forum since, as I said, all the data gets downloaded from the server so IIS would seem to be done already.

    An additional piece of information is, if she opens a tab in IE and the xap is downloaded and the service is called, it works.  If she opens another tab and repeats the same thing, it works again.  If she opens a third tab, it fails.

    We were able to reproduce that multiple times.  Restarting IE allowed it to work on the first tab again.

    If I had to guess, I would guess that something is causing IE to hit some internal memory limit or something.

    Anybody else have some wild guesses since we can't find out any more information using any tool we know to use?

    Why would the deserialization fail when it appears that all the data was transferred from the service?  And it doesn't fail every time.


    • Edited by Mark Tiede Thursday, June 1, 2017 1:34 PM
    Thursday, June 1, 2017 1:33 PM

  • Hi Mark Tiede,

    When you try to delete cookies, temporary internet files, internet history and password by following the steps below and check if the issue is still exists.

    1.Press Windows logo + R keys on the keyboard to open Run command box on the desktop.

    2.Type inetcpl.cpl in the command box and press Enter key on the keyboard.

    3.In General tab, click on Delete under Browsing history.

    4.Check the options you want to delete from the window (check Password option also) and click on Delete.

    Internet Explorer help:
    https://support.microsoft.com/en-us/products/internet-explorer


    >>If I had to guess, I would guess that something is causing IE to hit some internal memory limit or something.

    You can visit the following forum for more detailed information.

    Internet Explorer forum:


    I also suggest you ask your question in IIS forum, It may give you some different suggestions. After all, our Sliverlight site is hosted on IIS, some  IIS settings may be affected.

    IIS forum:

    Best Regards,

    Yohann Lu


    MSDN Community Support
    Please remember to click "Mark as Answer" the responses that resolved your issue, and to click "Unmark as Answer" if not. This can be beneficial to other community members reading this thread. If you have any compliments or complaints to MSDN Support, feel free to contact MSDNFSF@microsoft.com.

    Friday, June 2, 2017 6:36 AM
  • We already tried deleting stuff with IE. Even if that worked, it would only be a temporary fix. The real question is why is it failing at all.

    I was hoping someone else had run into this and would have suggestions from a Silverlight perspective.

    Friday, June 2, 2017 2:51 PM

  • Hi Mark Tiede,

    I found the following articles introduce how to huge amount of data from WCF service in Silverlight. Especially solve the generic NotFound exception.

    Retrieving huge amount of data from WCF service in Silverlight application
    https://smehrozalam.wordpress.com/2009/01/29/retrieving-huge-amount-of-data-from-wcf-service-in-silverlight-application/

    Handling Large Data Sets in Silverlight using WCF and Customized DataGrids
    https://www.codeproject.com/Articles/70834/Handling-Large-Data-Sets-in-Silverlight-using-WCF

    I hope it will help you.


    Note: This response contains a reference to a third party World Wide Web site. Microsoft is providing this information as a convenience to you. Microsoft does not control these sites and has not tested any software or information found on these sites; therefore, Microsoft cannot make any representations regarding the quality, safety, or suitability of any software or information found there. There are inherent dangers in the use of any software found on the Internet, and Microsoft cautions you to make sure that you completely understand the risk before retrieving any software from the Internet.


    Best Regards,

    Yohann Lu


    MSDN Community Support
    Please remember to click "Mark as Answer" the responses that resolved your issue, and to click "Unmark as Answer" if not. This can be beneficial to other community members reading this thread. If you have any compliments or complaints to MSDN Support, feel free to contact MSDNFSF@microsoft.com.

    Wednesday, June 7, 2017 2:50 AM
  • Thanks, but we already were using the parameters discussed there. Or at least most of them.

    I doubt changing anything there makes a difference.  Since it randomly works.  I would think if it works ONCE, then the parameters are all big enough for the data that we are retrieving.  And I wouldn't expect it to change when running it again with the same data, but it does fail, sometimes.

    Wednesday, June 7, 2017 12:40 PM

  • Hi Mark Tiede,

    From your further description, I suggest that you may can find the real failing question by analyzing the detailed error message for each occurrence of this situation.

    If you find useful detailed error messages, you can share with us.

    Best Regards,

    Yohann Lu


    MSDN Community Support
    Please remember to click "Mark as Answer" the responses that resolved your issue, and to click "Unmark as Answer" if not. This can be beneficial to other community members reading this thread. If you have any compliments or complaints to MSDN Support, feel free to contact MSDNFSF@microsoft.com.

    Thursday, June 8, 2017 2:45 AM
  • There is no further detail that we can find.
    Thursday, June 8, 2017 9:19 AM