QuickBooks multi user mode is an inbuilt feature in QuickBooks that permits multiple users to work on the same company file at the same time. This feature helps in increasing collaboration and enhances productivity. Each user must have the QuickBooks license to use the multi-user mode in QuickBooks. The issue with QuickBooks desktop multiple users mode arises when the user is trying to launch the company file which has been located on another PC. In this case, you may not receive any error but it will automatically display QuickBooks Multi user mode not working on another computer. Causes of QuickBooks Multi User Mode not working :- There can be a number of reasons that can cause the appearance of multi-user mode QuickBooks – QuickBooks is not installed on the server. The hosting settings are not properly configured. Firewall or antivirus software is not allowing communication between user computers. The database server is unable to open the QuickBooks company file.