QuickBooks was installed with the wrong license number and / or product code.
If the amount of users are inaccurate, this can be due to using the single user license for installation instead of the correct Multi-User license.
Once the license and product information in QuickBooks is accurate, the amount of users will also be accurate.
QuickBooks (change the license number only):
Note: If old product number remains after performing the above steps:
If the license or product numbers have not changed after updating the qbregistration.dat file, it will be necessary to restart your computer and verify the information again. If they are still not updated after a reboot, you will need to perform a clean install of QuickBooks.