[FIXED] QuickBooks Database Server Manager Network Diagnostics Failed

The QuickBooks Database Server Manager (QBDSM) is essential for enabling multi-user access to company files stored on a server. When its Network Diagnostics function fails, QuickBooks may be unable to connect to the file, triggering errors like H202, H505, or 6000 series. This guide provides a comprehensive, step-by-step approach to resolving the “Network Diagnostics Failed” issue and restoring seamless multi-user functionality.

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⚠️ What Does “Network Diagnostics Failed” Mean?

This error typically appears when you scan a folder using QBDSM and it fails to verify network connectivity or firewall permissions. It indicates that QuickBooks cannot establish a stable connection between the server and workstations.

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🔍 Common Causes

• 🔐 Windows Firewall blocking QuickBooks ports or executables
• 🧱 Damaged or misconfigured .ND (Network Descriptor) files
• 🌐 Network discovery or file sharing disabled
• 📂 Incorrect hosting configuration
• 🧠 QuickBooks Database Server Manager not running properly

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⚙️ Step-by-Step Solutions to Fix Network Diagnostics Failure

✅ Step 1: Restart QuickBooks Database Server Manager

1. Press Windows + R, type services.msc, and press Enter.
2. Locate QuickBooksDBXX (XX = your version, e.g., 29 for 2019).
3. Right-click and select Restart.
4. Ensure Startup Type is set to Automatic.

💡 Pro Tip: Restarting the service often resolves temporary connectivity issues.

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🔄 Step 2: Re-scan the Company File Folder

1. Open QuickBooks Tool Hub.
2. Go to the Network Issues tab.
3. Click QuickBooks Database Server Manager.
4. Browse to the folder containing your company file and click Scan.
5. Wait for the scan to complete and check if the diagnostics pass.

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🧰 Step 3: Configure Windows Firewall

1. Open Windows Defender Firewall > Advanced Settings.
2. Create Inbound and Outbound Rules for the following ports:

QuickBooks Version	Ports to Open
2022	8019, 56728–56730
2021	8019, 56727–56729
2020	8019, 56726–56728

3. Add exceptions for these executables:
   • QBDBMgrN.exe
   • QBCFMonitorService.exe
   • QBW32.exe

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🔐 Step 4: Verify Hosting Configuration

1. Open QuickBooks on each workstation.
2. Go to File > Utilities.
3. If you see Host Multi-User Access, hosting is OFF—do nothing.
4. If you see Stop Hosting Multi-User Access, hosting is ON—click to disable.

⚠️ Only the server should host the company file.

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🛠️ Step 5: Rename .ND and .TLG Files

1. Navigate to the folder containing your company file.
2. Locate files with the same name but extensions .ND and .TLG.
3. Rename them:
   • YourCompanyFile.nd → YourCompanyFile.nd.old
   • YourCompanyFile.tlg → YourCompanyFile.tlg.old
4. Open QuickBooks and try accessing the file again.

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🧪 Step 6: Enable Network Discovery and File Sharing

1. Go to Control Panel > Network and Sharing Center > Advanced Sharing Settings.
2. Turn on Network Discovery and File and Printer Sharing.
3. Save changes and restart your computer.

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