The Plex Media Server software is installed as a Package on Cloudforest.
You need Administrator permission to do this:
From any browser login using an administrator account to Cloudforest at quickconnect.to/Cloudforest
Click on the menu (top left) and click on Packages app
Click for the PLEX Media Server in the Installed Packages list.
Check that the Staus is "Running".
If the status is "Stopped" then select Run from the action menu to restart.