: If you’re seeing the error “QBDBMgrN not running on this computer,” it means that the QuickBooks Database Server Manager (QBDBMgrN.exe) is not functioning properly, preventing multi-user access. This issue typically occurs due to a misconfigured firewall, outdated QuickBooks version, or a corrupted installation of the Database Server Manager.

Steps to Fix the Issue:
Restart QuickBooks Database Server Manager

Press Windows + R, type services.msc, and hit Enter.
Locate QuickBooksDBXX (where XX is your QuickBooks version).
Right-click and select Restart.
Update QuickBooks & Windows Firewall Settings

Ensure QuickBooks is up to date.
Open Windows Firewall, go to Advanced Settings, and allow QuickBooks through inbound/outbound rules.
Use QuickBooks File Doctor

Download and run the QuickBooks Tool Hub.
Go to Company File Issues and run QuickBooks File Doctor.
Reinstall QuickBooks Database Server Manager

Uninstall it from Control Panel > Programs & Features.
Reinstall from the QuickBooks installation setup.
If the problem persists, contact QuickBooks Support at 1-855-738-2891 for expert assistance.