iManager fails to authenticate with "HTTP Status 404 - /nps/servlet/imanauthentication"

After patching OES2SP3 to current and/or after installing the latest iManager plugins, launching iManager fails after the authentication screen with the message "HTTP Status 404 - /nps/servlet/imanauthentication"

Backup the /var/opt/novell/iManager/nps/WEB-INF/web.xml file, then replace it with a copy from a known good iManager instance, ensuring the permissions are set correctly (-rw-r--r-- 1 wwwrun www).

Note: Server-based standalone iManager instances use the filename web.xml, whereas workstation iManager instances use workstationweb.xml.  In both cases these files will be renamed to web.xml after a successful install.

During some installs the newweb.xml still exists and contains the content needed in the web.xml.  The web.xml can be renamed, in this case, to web.xml.old and the newweb.xml renamed to web.xml.

Restart novell-tomcat and refresh the browser that is attempting to launch iManager and operation should return to normal.

After investigating it was discovered that at some point during either the OES2 patching process, or during the updating the iManager plugins themselves, that the /var/opt/novell/iManager/nps/WEB-INF/web.xml file becomes corrupted, and is missing several sections, including...

<servlet-mapping>
        <servlet-name>portal</servlet-name>
        <url-pattern>/servlet/imanauthentication</url-pattern>
  </servlet-mapping>

... which produces the error in question.

It should be noted that sometimes even after fixing the underlying issue one will continue to see the problem even after restarting novell-tomcat.  If this is the case, deleting the cache directory and everything below it for novell-tomcat, located at /var/opt/novell/tomcat5/work/Catalina generally solves the issue.

**UPDATE** This issue has been fixed with the iManager 2.7.6 release.