The Tomcat server can sometimes lose its mapping to the home page (http://<ump_server>/web/guest) and will only display the webapp file structure.
This renders UMP useless as users cannot log in and navigate to other pages / portlets.
The home page redirect can be restored by archiving the ROOT webapp folder, re-deploying ump.zip, unpacking the ROOT.war file, then restoring the original ROOT webapp folder.
This can be accomplished through the following procedure:
1) Stop 'wasp'
2) On the UMP server, back up: <nimsoft>/probes/service/wasp/webapps/ROOT folder
3) Archive <nimsoft>/probes/service/wasp/webapps/ROOT.war
4) Redeploy 'ump.zip' to the UMP server
5) Restart 'wasp'
6) Stop 'wasp'
7) On the UMP server, rename <nimsoft>/probes/service/wasp/webapps/ROOT to 'ROOT_new'
8) Import the archived ROOT folder file back to <nimsoft>/probes/services/wasp/webapps
9) Restart 'wasp'
Verify that the URL http://<ump_server> automatically redirects to: http://<ump_server>/web/guest and that users can properly log in and navigate.