Multiuser mode lets multiple users work on a company file all at once, from different workstations. You can use multiuser mode in one of two ways: through server-workstation setup or server-only install. In QuickBooks Desktop, go to the File menu and hover over Utilities. Select Host Multi-User Access. QuickBooks Multi-user mode is a feature inbuilt into QuickBooks and has aided a lot of businesses on working with the application. This error generally occurs when users try to launch a company file that is stored on a server. Another common issue faced by users is that QuickBooks continues to work in a single-user mode.