🧩 QuickBooks Error 6123, 0 – Fix with Expert Guide

QuickBooks Error 6123, 0 typically occurs when users attempt to open, restore, or upgrade a company file. The error message may read:

“Error -6123, 0: Connection to the QuickBooks company file has been lost.”

This issue can disrupt access to your financial data and is especially common in multi-user environments or during file restoration from backups.

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⚠️ What Causes Error 6123, 0?

According to verified sources, common triggers include:

• 🧱 Corrupted or damaged company file (.QBW)
• 🔄 Incomplete or interrupted restore or upgrade process
• 🌐 Network connectivity issues between server and workstations
• 🛡️ Firewall or antivirus blocking QuickBooks services
• 🔒 Background processes like antivirus or remote access tools interfering with QuickBooks
• 🧩 Damaged .ND or .TLG configuration files

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🛠️ Step-by-Step Troubleshooting Guide

✅ Step 1: Use QuickBooks Tool Hub

Instructions:

1. Download the latest version of QuickBooks Tool Hub.
2. Open Tool Hub and go to Company File Issues.
3. Click QuickBooks File Doctor.
4. Browse and select your company file.
5. Let the scan complete and follow any repair prompts.

This tool automatically detects and repairs file corruption and network issues.

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🔧 Step 2: Rename .ND and .TLG Files

Instructions:

1. Navigate to the folder containing your company file.
2. Locate files with the same name as your company file but ending in .ND and .TLG.
3. Right-click each and rename them (e.g., CompanyFile.nd.old and CompanyFile.tlg.old).
4. Open QuickBooks and rescan the folder using Database Server Manager.

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🧰 Step 3: Restore the Backup File Locally

If you’re restoring a backup, avoid doing it over a network.

Instructions:

1. Copy the backup file (.QBB) to your local drive.
2. Open QuickBooks and go to File > Open or Restore Company > Restore a Backup Copy.
3. Browse to the local file and complete the restore process.

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🛠️ Step 4: Disable Background Applications

Remote access tools or antivirus software may interfere with QuickBooks.

Instructions:

1. Press Ctrl + Shift + Esc to open Task Manager.
2. End tasks related to LogMeIn, GoToMyPC, or antivirus software.
3. Retry opening or restoring the company file.

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🛡️ Step 5: Configure Firewall and Antivirus

Instructions:

1. Add QuickBooks and Database Server Manager as exceptions in your firewall.
2. Temporarily disable antivirus software and retry the operation.
3. Re-enable protection after successful access.

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🧹 Step 6: Perform a Clean Install of QuickBooks

If the error persists:

Instructions:

1. Uninstall QuickBooks via Control Panel > Programs and Features.
2. Use Tool Hub’s Clean Install Tool to remove residual files.
3. Reinstall QuickBooks using your license and product key.

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🧠 Pro Tips

• Always back up your company file before making changes.
• Run QuickBooks as Administrator to avoid permission issues.
• Avoid using mapped drives; use UNC paths instead (e.g., \\ServerName\SharedFolder).
• Keep QuickBooks and Windows OS updated to the latest release.

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