Solution to TOMCAT ERROR 404
Download FIX - CA Service Desk Manager 14.1 Solutions & Patches
If these actions don't works, probably your server uses the same CA Service Desk tomcat port for some-other application, make shore using netstat command
netstat -an |find "<tomcat port>"
netstat -an |find "8080" (standard)
You can change this port, run pdm_configure.