tomcat WAR 404 not found

Problem:

A functional and well tested WAR was not reachable on a new tomcat instance.

Solution:

The new tomcat was for java 1.7 apps and the WAR was a 1.8 java compiled app, so the tomcat deployed the war without errors and the app was showing 404 not found.

In the webapp folder of the tomcat you will find your unpacked war and in this unpacked war folder, you will find the web inf folder and in the subfolders of this folder you will find java classes. On these class files you can check the compile time version with javap -verbose filename