To fix QuickBooks multi-user mode error 6210, 0, follow these steps:
- Restart QuickBooks Database Server Manager: Close QuickBooks and go to the Windows taskbar, right-click the QuickBooks Database Server Manager icon, and choose "Stop." After that, click on "Start" to restart it.
- Check for System Updates: Ensure your computer has the latest Windows updates installed.
- Run QuickBooks File Doctor: Download and run the QuickBooks File Doctor tool from the Intuit website to detect and repair any data-related issues.
- Verify Hosting Settings: In QuickBooks, open "File," select "Utilities," and check if "Host Multi-User Access" is enabled. Disable it, and then enable it again.
- Check Antivirus and Firewall: Ensure that QuickBooks and its components are allowed through the firewall and antivirus software.