QuickBooks Error 6007: Fix “QuickBooks Is in Single-User Mode” / Sync Manager Error

What Is QuickBooks Error 6007?

QuickBooks Error 6007 typically appears when trying to open or connect to your company file in multi-user mode — instead, QuickBooks notifies you that:

“Error 6007: There was an error while connecting to your company file: QuickBooks is in single-user mode.”

This issue often involves the Sync Manager, file permissions, or hosting configuration. For an in-depth walkthrough, this guide will help you resolve it step-by-step.

Description:
Resolve QuickBooks Error 6007 (“QuickBooks is in single-user mode”) with our comprehensive 2025 guide. Learn why the error appears, how to fix it through Sync Manager reset, renaming ND/TLG files, and how to prevent it later.

Topics- QuickBooks Error 6007, QuickBooks 6007 fix, QuickBooks sync manager error, QuickBooks single-user mode connection issue, rename ND file QuickBooks, TLG file QuickBooks 6007, QuickBooks multi-user access error, QuickBooks hosting error

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What Causes QuickBooks Error 6007?

Here are some of the most common triggers:

1. Using Single-User Mode Instead of Multi-User

   • Your company file may already be opened exclusively by someone else.

2. Sync Manager Is Outdated or Corrupted

   • Damaged Sync Manager files can block correct synchronization.

3. Corrupted Company File (.QBW)

   • File corruption may prevent proper access or multi-user sharing.

4. Network / Hosting File Misconfiguration

   • Incorrect hosting settings or file corruption in ND / TLG files.

5. Firewall or Antivirus Interference

   • Security tools may block QuickBooks services or sync-related processes.

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How to Fix QuickBooks Error 6007 (2025 Guide)

Here are the proven methods to resolve this error:

Solution 1: Log in with QuickBooks Admin Credentials

• Close QuickBooks if it’s open.

• Reopen QuickBooks using an administrator-level user account.

• Try accessing the company file again.

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Solution 2: Switch User Mode Correctly

• In QuickBooks → Go to File → Utilities.

• Select Switch to Multi-User Mode (if required) or Switch to Single-User depending on your setup.

• Ask other users to close QuickBooks, then reopen together in the correct mode.

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Solution 3: Update or Reset Sync Manager

Because Error 6007 is frequently connected to Sync Manager:

1. In QuickBooks, go to Help → Sync Manager.

2. Choose Reset Sync (or similar option in your version).

3. After reset, log in again and let Sync Manager resynchronize.

4. Try opening the company file.

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Solution 4: Rename the ND and TLG Files

These files enable QuickBooks multi-user access. If they’re corrupt, renaming helps:

1. Close QuickBooks.

2. Navigate to the folder where your company file (.QBW) is stored.

3. Find the .ND and .TLG files matching your company file name.

4. Right-click → Rename → append .OLD (e.g., Company.qbw.nd.OLD).

5. Reopen QuickBooks — QuickBooks will regenerate those files automatically.

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Solution 5: Check Firewall / Antivirus

1. Temporarily disable your firewall or antivirus.

2. Try connecting to the company file again.

3. If it works, add QuickBooks Desktop, QuickBooksDB, and Sync Manager as exceptions/exclusions in your security software.

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Solution 6: Clean Install QuickBooks (if Needed)

If none of the above work:

1. Uninstall QuickBooks from your computer.

2. Open QuickBooks Tool Hub → Installation Issues → Clean Install Tool.

3. Run the Clean Install, then reinstall QuickBooks with the latest installer.

4. Restore your company file and try opening it again in the correct mode.

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How to Prevent QuickBooks Error 6007 in Future

• Make sure all users switch correctly to multi-user mode when needed.

• Regularly update Sync Manager and QuickBooks.

• Maintain backups of your company file (.QBW).

• Run QuickBooks File Doctor periodically to detect corruption.

• Keep your firewall or antivirus configured to allow QuickBooks processes.

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📌 FAQs (Frequently Asked Questions)

Q1: What exactly does QuickBooks Error 6007 mean?
It means QuickBooks failed to connect in multi-user mode because it thinks the company file is locked or in single-user mode, often due to Sync Manager or file access issues.

Q2: Will renaming ND and TLG files delete my data?
No. These are log files, not your actual data. QuickBooks will regenerate them safely when reopened.

Q3: Can I fix this by myself or do I need a QuickBooks expert?
Many users can fix this using the steps above. But if you are uncomfortable or the error recurs, you may want to reach out for professional help.

Q4: Does a clean install erase my company file?
No, your .QBW file is separate and will remain safe if backed up before reinstalling QuickBooks.

Q5: Why would my firewall or antivirus block QuickBooks?
QuickBooks, QuickBooksDB (database service), and Sync Manager use network and system services — firewalls or antivirus software might block those components if not whitelisted.