After upgrading GeoEvent from 10.2.2 to 10.3.1 we could not open the login for GeoEvent.
Our GeoEvent service is running but we are getting a no service was found error and a 404: Page Not Found message instead of the manager login page. GeoEvent logs showed the old configurations were maintained during the upgrade.
Log file location: C:\Program Files\ArcGIS\Server\GeoEvent\data\log\karaf.log