AuthentiX can cause IIS 6 to crash when moving out of Isolation Mode

The AuthentiX FAQ gives information on how to make AuthentiX the application work with IIS 6 sucessfully, but applying this fix, the site has not worked regardless of the change specified. Since the current version used is out of support, and the client is looking to upgrade to Forms Authentication, I had to make do with the problem.

Over the weekend, I had to fix an issue where IIS 6.0, whilst running in IIS 5 Isolation Mode, suddenly (possibly due to a Windows Update) completely crashed IIS, so that it was unusable. IIS 6 kept coming up with the error “The path for the specified directory cannot be found”, showing a red triangle in IIS, making it unable to start up – at all!

The only way to switch it back into IIS 5 Isolation Mode is to:

1. Stop IIS Admin Service from the Services MMC plug-in
2. Open the %WINDIR%\system32\inetsrv\Metabase.xml
3. Save a backup of it.
4. In Metabase.XML, Look for the XML:

   <IIsWebService>
   ...
       IIs5IsolationModeEnabled="FALSE"
   ...
   </IIsWebService>

5. Change the value from "FALSE" to "TRUE".
6. Restart the IIS Admin Service from the Services MMC Snap-in.

IIS should restart and come back to life in IIS5 Isolation Mode.