A QuickBooks error message that reads QBDBMGrN Not Running On This Computer indicates that the QuickBooks Database Server Manager (QBDBMgrN) is not operational. This stops access to multi-user mode. Outdated software, firewall settings, or service interruptions could be the cause. The problem may be fixed by restarting the service or changing the firewall settings.Call 1.855.738.2784 to speak with a QB support representative.