Openedge 12 fathom won't start

An error is returned when trying to start OEM via command line. 
When running fathom -start an error is returned. 
 

OEM starts fine when the service "OpenEdge Management Service for OpenEdge 12.0" is running.

In OE 12, OEM is a separate independent process from the AdminServer running on as a PASOE instance webapp. 
The OpenEdge Management webapp is configured by default to start as a service on Windows under a Local System Account.  
The command fathom -start must be run from a CMD session with elevated administrator privileges.

https://www.windows-commandline.com/system-error-5-has-occurred/

Windows: Run the command in a elevated CMD session.

https://www.windows-commandline.com/open-elevated-command-prompt/

Linux: Setup an additional Systemd script which defines an After and Requires option.
Based on examples from article if a systemd service is defined and named admsrvc.service then a systemd service for fathom in 12.0 may also be created and establish a requirement and statement of ordering using the below example:
 

#
[Unit]
Description=OpenEdge Management for OE 12.0
After=network.target admsrvc.service
Requires=admsrvc.service

[Service]
Environment=DLC=/usr/dlc
ExecStart=/usr/dlc/bin/fathom -start
ExecStop=/usr/dlc/bin/fathom -stop
Type=forking

[Install] 
WantedBy = default.target

Enable service to start when OS restarts
 

systemctl enable <service name>

Alternatives:

• If scripting is needed start the service via command line instead of using the fathom command (https://stackoverflow.com/questions/133883/stop-and-start-a-service-via-batch-or-cmd-file).
• Change the user the service runs as, to the same user that will be executing the fathom command.
• Disable the OEM service and change psc.as.service to false in the $OEMGMT/conf/appserver.properties file, this way OEM will be started via command line as the user that issues the command.

Progress Articles:

 How to autostart AdminService on Linux with systemctl scripts?    
 Which licenses include the OpenEdge Explorer product ?  
Frequently Asked Questions (FAQ) regarding the removal of JDK from OpenEdge installations in 12.x.
OpenEdge 12 Explorer fails with Error - HTTP Status 404 - Not Found