Tomcat can get confused. Today I dealt with an issue where Tomcat just wouldn't deploy a war file on one of our webapp servers, so the app was unavailable. The first symptom of the problem was a Tomcat 404 page.
type Status report message /mywar/default description The requested resource (/mywar/default) is not available.
and then
bin/shutdown.sh && tail -f logs/catalina.out bin/startup.sh && tail -f logs/catalina.out
find missing oracle.jdbc.driver
btw, if the server shutdown shows erro, try to env and see the catalina_home, base jre_home are all set up correclty