The following error occurs when opening a QuickBooks Desktop company file:
You've exceeded the maximum number of users who can access the company file at one time.
This message can occur if:
Note: If you have a server computer running the QuickBooks Database Server only and not the QuickBooks Desktop application, you do not need to perform these steps on that computer.
Please follow this link to get information on renaming the .ND file
For additional information, refer to About QuickBooks licenses (an overview) and Troubleshoot QuickBooks licenses.