Common symptoms
- QuickBooks asks you to switch to multi-user mode, then shows H202 or H505
- The company file opens on the host but not from one or more workstations
- Multi-user access worked before an update, restart, or network change
Before you begin
- Confirm which computer physically stores the .QBW company file
- Ask every user to close QuickBooks before changing hosting or services
- Have Windows administrator access available on the host and affected workstation
Back up your data before changing company-file components, services, firewall rules, or permissions. Never delete the .QBW company file as a troubleshooting step.
1. Confirm that only the correct computer is hosting
Hosting is a setting for each QuickBooks Desktop installation—not for the company file itself. In a typical setup, the computer storing the company file hosts it; workstations do not.
- On each workstation, open QuickBooks without opening the company file.
- Choose File → Utilities.
- If the menu says “Stop Hosting Multi-User Access,” that workstation is hosting. Stop hosting there.
- On the computer storing the file, confirm the Database Server Manager is installed and the folder containing the company file has been scanned.
Multiple computers trying to host the same file can produce intermittent errors that look like firewall trouble.
2. Test the path before changing the firewall
From the affected workstation, verify that Windows can resolve and reach the host computer. Then browse to the shared folder and confirm that the company file is visible.
- Open File Explorer and enter the host path, such as \SERVER\QBFiles.
- If the share does not open, resolve Windows networking, name resolution, or share permissions first.
- If the share opens, test whether you can create and delete a harmless text file in that folder. Do not test with the company file.
QuickBooks cannot repair an underlying Windows connectivity or permission failure. Fix that layer before continuing.
3. Check the database service and rescan the folder
QuickBooks Database Server Manager runs as a Windows service named QuickBooksDBXX, where the number varies by QuickBooks version.
- On the host, open Windows Services and locate QuickBooksDBXX for the installed version.
- Confirm the service is running and configured to start automatically.
- Open QuickBooks Database Server Manager and scan the folder that contains the .QBW file.
- Retry multi-user mode from one workstation before changing anything else.
4. Review firewall permissions
Allow the QuickBooks programs and version-specific ports required by your installed version. Port requirements are not identical across every QuickBooks release, so avoid relying on one universal port number.
- Use Intuit’s current firewall configuration article to identify the executable and port rules for your version.
- Apply rules on the host first, then retry the connection.
- If third-party endpoint security is installed, review its event log or policy rather than disabling protection broadly.
A brief controlled test may help isolate a cause, but protection should be restored immediately and replaced with narrow allow rules.
5. Re-create the network descriptor only when needed
The .ND file sits beside the company file and tells QuickBooks how to contact its database server. Rescanning the folder normally regenerates it.
- Make sure all users are out of QuickBooks.
- Locate the .ND file with the same base name as the .QBW file.
- Rename the .ND file by appending .OLD; do not delete the .QBW company file.
- Rescan the folder in Database Server Manager and test again.
Verify the result
Test one workstation before bringing everyone back in.
- Open the company file from its normal network path.
- Switch to multi-user mode and sign in with a separate QuickBooks user.
- Close and reopen the file once to confirm the repair survives a fresh connection.
- Record what changed and keep a current backup.
Sources and review notes
This guide is independently written and reviewed against the official references below. Product behavior can vary by version and network environment.
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