Strange behaviour JavaScript in IE8 - Object Expected only when using WAN link but not when Fiddler is active RRS feed

  • Question

  • Hi,

    We are using JavaScript and IE8. When working across a WAN link 9 out of 10 times an Object Expected occurs when IE8 wants to execute 'eval("ExtFunction('para1','para2')")

    The 'ExtFunction' is defined in another JS file. This file where the function is defined is present in the cache (debugged with F12). The function call and parameters within the eval() is always the same and works well when working in a LAN environment (server and client on fast network). When executing the same script using a slower (MPLS) network, an Object Expected message appears 9 out of 10 times.


    - We do not have any issues when using Firefox 3.5, 3.6, IE9 or IE10. We do have to use IE8 because of certification and compliancy.

    - We do not have any issues with IE8 on a fast-connection with the back-end server. When using MPLS (incl. firewall) it won't work 9 out of 10 times.

    - Using F5 to refresh won't help, still 9 out of 10 times it fails.

    - Using a local proxy server ( client -> proxy -> (WAN) -> Back End web server ) works as well !!

    The most peculiar is the fact that when running the test with Fiddler activated (to debug the HTML connection/activity like HTTPLook does), it will always work even over the WAN!

    How can this issue be solved without requiring a running Fiddler? 

    - Mike.

    • Edited by MyKey Mike Wednesday, May 22, 2013 2:12 PM adding proxy works
    Wednesday, May 15, 2013 3:13 PM

All replies

  • Hi,

    Thnx for the tip 'curiously idle'. Using a network monitor like netmon or wireshark does not make any difference. It seems the application Fiddler acts as a proxy that makes the issue disappear.

    Anyone an idea how I can troubleshoot the issue, or can explain whats going on?

    - Mike

    Tuesday, May 21, 2013 6:08 AM