QuickBooks multi-user mode allows multiple users to work on your QuickBooks company file at the same time. However, you may experience technical issues when switching from single-user mode to multi-user mode. Such errors are sent to the server computer without being displayed to the system. The QuickBooks multi-user mode not working issue can further trigger the QBDBMgrN not running on this system. This issue related to multi-user mode can reduce productivity, prevent business goals from being achieved, and lead to financial losses.