The error message QuickBooks Multi-User Mode not working stops several users from accessing the firm file at once.  Incorrect hosting settings, firewall constraints, or issues with the QuickBooks Database Server Manager could be the cause of this problem.  For smooth multi-user operation, troubleshooting include confirming hosting, setting up firewall ports, and guaranteeing network connectivity.  For QuickBooks support, please call the friendly help line at 1.855.738.2784.