Attachment Upload Failed - Error 404 - not found

Version 1

    Details

    Sometimes attachments cannot be uploaded in ITSM 6.x / 7.x ; this can happen 1 out of 3 tries.
    The upload aborts with the error message: "Attachment Upload Failed - Error 404 - not found". The Smart Client is no longer responding.


    Resolution

    Configure double escaping

    To configure double escaping, use the following syntax:

    1. Open a CMD prompt as an Administrator
    2. Type CD C:\Windows\System32\inetsrv
    3. Appcmd set config /section:requestfiltering /allowdoubleescaping:true
    4. Perform an IISreset

    See also http://www.iis.net/learn/manage/configuring-security/configure-request-filtering-in-iis