Note: This is also applicable to Interset 4.x.
If the Reporting service is not started, you may receive an HTTP 502 error when connecting to the Reporting URL (e.g. http://<REPORTING_SERVER>).
To resolve this, confirm if the Reporting service is running using the jps command and searching for "investigator-3-SNAPSHOT.jar". If this is not running, start it by using the nohup java –jar /opt/interset/reporting/investigator-3-SNAPSHOT.jar server /opt/interset/reporting/investigator.yml & command.