To address QuickBooks multi-user mode not working, first, ensure all users are using the same version of QuickBooks. Verify that hosting is enabled on the server and that firewall settings allow QuickBooks connections. Next, run the QuickBooks Database Server Manager and rescan the company file folder. Check network connectivity and permissions to ensure users have adequate access. If the issue persists, try disabling the antivirus or firewall temporarily. Consider reinstalling QuickBooks Database Server Manager you can also contact our experts by dialing us at +1 855-856-0053 and we will provide you with instant technical assistance.