RHDS - Starting a Directory Server instance with systemctl "failed because a configured resource limit was exceeded."

Issue

Trying to start a Directory Server instance with systemctl fails with the following error message:

# systemctl restart dirsrv@non_existing_instance
Job for dirsrv@non_existing_instance.service failed because a configured resource limit was exceeded. See "systemctl status dirsrv@non_existing_instance.service" and "journalctl -xe" for details.
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