Imunify360 not working on Ubuntu: Imunify service is not started

Symptoms

• In an attempt to access the Imunify360 page in Plesk the following error is shown:

  CONFIG_TEXT: Package immunify360-firewall is installed. Please wait for imunify360 service to start and reload the page.

  ---

  CONFIG_TEXT: Imunify service is not started

  ---

  CONFIG_TEXT: Imunify agent is not running
  Try to start it by executing 'service imunify360 start' or contact support

Cause

The imunify360 service is in the stopped state.

Resolution

1. Log into Plesk.
2. Go to Tools & Settings > Scheduled Tasks (Cron jobs) > Add Task.
3. Perform the following:

• Select Task Type as Run a command
• In the Command * field paste the text below:
  

  CONFIG_TEXT: systemctl start imunify360.service

• From the drop-down menu System user select root
  Click on the screenshot below to expand 
  
• Press the Run Now button to start the imunify360 service.

Note: if the page is still not accessible, await for up to 60 minutes, according to the extension vendor recommendation.