If you have issues after upgrading to a newer version of Symantec Endpoint Protection Manager, check out the logs at .tomcatlogs. There's a file called catalina.err which usually provides some degree of more useful error messages than the one in Windows Event logs. Additionally, other files such as scm-server.log are also useful.
Sometimes after upgrading, the Upgrade Wizard does not run, and the database does not get updated, resulting in SEPM not starting up. A look in the catalina.err reveals that the the database schema and server schema are not compliant.
You can manually run the Upgrade Wizard. Navigate to .bin and run the script upgrade.bat. It will start the wizard and continue with the upgrade of your database.