IBM Support

Viewer/Query Studio Javascript errors accessing Cognos through VPN

Technote (troubleshooting)


After 10.2 upgrade, users behind a reverse proxy cache getting javascript errors in Cognos Viewer, Query Studio and Business Workspace Advanced. The proxy cache was out of date and serving up the old 10.1.1 javascripts,. Refreshing the cache resolves.


Several users of the customer's system access the network through a VPN connection with a reverse-proxy cache (like a web accelerator). After upgrading to 10.2, all users behind the proxy found they were unable to view report outputs in the Cognos Viewer or see the metadata in Query Studio or Business Workspace Advanced. Various javascript errors were seen with this tools.


It appears that the reverse proxy cache was sending the wrong version of some of the web resources. Once this cache was refreshed, functionality was restored.

Diagnosing the problem

We used Fiddler to trace the browser requests, and noticed that even starting with a new browser after clearing the local cache, all the javascript requests were returned with a "304 Not Modified" response. This indicates that the request was satisfied with cached data. The javascript error in "Cognos Viewer" wasn't visible until we turned on the "Script Debugging" option in Internet Explorer.

Resolving the problem

Using the fiddler option "Disable Caching" allowed the test workstation to function properly and also appeared to update the proxy cache, as all other workstations started working as well (even without fiddler). Likely, we could also have requested that the proxy devices get reset

Document information

More support for: Cognos Business Intelligence
Cognos Viewer

Software version: 10.2

Operating system(s): AIX, Windows

Reference #: 1641167

Modified date: 18 June 2013

Translate this page: