Hi JK

Thanks for your solution to fixing the redirection loop. I have asked our hosting provider about carrying out your suggestions and they say that the AJAX Extensions are already installed on the server, and that they can't restrat IIS because it takes 30 mins to cycle and would affect the availability of a 1000 other website. Is there another way of achieving this?

Thanks

Regan

I saw this begin happening to one of my client's sites recently and NONE of the fixes suggested here in the forums or on the various google results resolved the issue.

In this case, the client had installed or changed something (could never determine the exact cause), and if you went to the URL of the site, the loop would occur. If you went to the site?tabid=36, then the site would come up fine. After login if any attempt was made to change the skin, the skins page would begin looping.  Everything else worked fine.  I suspected a skin problem so I replaced the skin on the server directly with a different one in the existing selected skin directory.  No change.

I then copied the web_.config from the siteroot\config\Backup_20081016203 (differs depending on the last date/time the site wrote to the web.config) directory and that fixed the issue. Apparently, the updated web.config had an entry in it that caused the looping.

Possibly that solution will help others as well