This error occurs when there is a conflict in file access, such as:

The company file is open in single-user mode on another workstation

The file is stored in a read-only network folder

Remote access sessions are keeping the file locked

File corruption or damaged .ND/.TLG files

If you need immediate expert assistance with QuickBooks Error 6073 99001, contact certified professionals.

Common Causes of QuickBooks Error 6073 99001
Cause Explanation
Single-User Mode Conflict The file is open on another computer in single-user mode
Read-Only Folder The company file is located in a network folder with read-only permissions
Remote Access Sessions LogMeIn, GoToMyPC, or similar tools leave the file locked
Linux Server Conflicts Multiple login credentials accessing the same shared folder
Corrupted .ND/.TLG Files Damaged network data or transaction log files
Incorrect Hosting Settings Multi-user hosting is not properly configured
Symptoms of QuickBooks Error 6073 99001
Error message: "QuickBooks is unable to open this company file"

QuickBooks crashes when opening the company file

File appears locked even when no other users are online

QuickBooks freezes during file access attempts

Multi-user mode fails to load properly

Step-by-Step Solutions to Fix QuickBooks Error 6073 99001
Solution 1: Run QuickBooks File Doctor
The QuickBooks File Doctor is Intuit's primary tool for fixing company file and network issues .

Steps:

Download the latest QuickBooks Tool Hub from the official Intuit website

Install and launch the Tool Hub

Select Company File Issues from the menu

Click Quick Fix My File first as a quick option

Then select Run QuickBooks File Doctor

Choose your company file from the dropdown or browse for it

Select Check your file and network (recommended)

Enter your QuickBooks admin password and click Next

Wait for the scan to complete (may take 10-20 minutes)

Note: If QuickBooks File Doctor does not open automatically, search for it manually in Windows and open it .

Solution 2: Manually Resolve Single-User Mode Conflicts
If the error is caused by single-user mode conflicts, use this approach :

Case 1: File open on another workstation in single-user mode

Close QuickBooks on all computers in the network

Open the company file on the Host computer only

Go to the File menu and select Switch to Multi-User Mode

If the issue persists, reboot all workstations

Case 2: File open in single-user mode on the Host computer

Go to the File menu and select Close Company

Reopen the file: File → Open or Restore Company

Select Open a company file and click Next

Select your company file

Choose Open file in multi-user mode and click Open

Solution 3: Check and Fix Folder Permissions
If the company file is in a read-only folder, adjust permissions :

Navigate to the folder containing your company file on the host computer

Right-click the folder and select Properties

Go to the Security tab

Select the user experiencing issues and click Edit

Check Allow for the following permissions:

Full Control

Modify

Read & Execute

Read

Click Apply and OK

Solution 4: Run Quick Fix My Program
Remote access sessions can leave phantom users logged in :

Open the QuickBooks Tool Hub

Select Program Problems from the menu

Click Quick Fix My Program

Wait for the repair process to complete

Restart QuickBooks and try opening your company file

Solution 5: Rename .ND and .TLG Files
Damaged network data files can cause this error :

Close QuickBooks completely

Open the folder containing your company file

Locate files with the same name as your company file but with .ND and .TLG extensions

Right-click each file and select Rename

Add .old to the end of each filename

Reopen QuickBooks—fresh .ND and .TLG files will be created automatically

Solution 6: Verify Hosting Settings
Only the server should host multi-user access :

On the server computer, open QuickBooks and your company file

Go to File → Utilities → Host Multi-User Access

Select Yes and click OK

Verify that hosting is disabled on all workstations

Reboot all computers and try accessing the file again

Frequently Asked Questions (FAQs)
Question Answer
What is QuickBooks Error 6073 99001? A multi-user mode error preventing company file access, typically caused by single-user mode conflicts, read-only folders, or network issues
How do I fix QuickBooks Error 6073 99001? Run QuickBooks File Doctor, switch to multi-user mode, adjust folder permissions, or rename .ND/.TLG files
Can remote access cause this error? Yes. Remote software like LogMeIn or GoToMyPC can leave sessions active, locking the file
Is my company file at risk? No. Your financial data is safe. The issue is with file access and network configuration, not data corruption
What if none of the solutions work? Contact professional support for advanced troubleshooting
Final Conclusion
QuickBooks Error 6073 99001 is a common but completely fixable multi-user mode error. By following the step-by-step solutions in this guide—running QuickBooks File Doctor, switching to multi-user mode, adjusting folder permissions, and renaming .ND/.TLG files—you can quickly restore access to your company file.

If you are unable to resolve QuickBooks Error 6073 99001 on your own, professional support is available.