Fix QuickBooks Error 6123 Like a Pro with These Expert Fixes

Published by David Miller, Last Updated On :

Quickbooks error 6123

QuickBooks is revolutionary accounting software that allows you to carry out all your accounting processes with ease. This software makes managing the accounting side of a business relatively seamless. However, all this does not discount that QuickBooks is prone to technical glitches and errors. One of the most common ones is QuickBooks error 6123. The error frequently arises in multi-user environments. Although sometimes you may fix this problem by following the instructions that the software gives, it’s not always the case. In this article, you’ll find out in detail about this error, its causes, and what you can do to fix it. 


What is QuickBooks Error 6123?

Users usually find an error message that says ‘Error 6123, 0 Connection to the QuickBooks company file has been lost.’ Generally, users are advised to adhere to the standard troubleshooting process to fix the company file. It involves running the QuickBooks File Doctor and making an update to the QuickBooks Database server manager. 

Although you may find relief by implementing these measures, sometimes they will not yield the desired results. In such cases, you will need to carry out additional troubleshooting. 


Why Does QuickBooks Error 6123 Occur?

Many factors result in this error message in different QuickBooks versions like QuickBooks 2018, 2019, and the like. The chief reasons leading to this company file error include the following.

  • There are damaged QB data files.
  • Users selecting the Block Web Bugs filter in their McAfee antivirus program.
  • Damaged or corrupt Windows operating systems also result in QuickBooks error code 6123.
  • Blockage by firewall prevents communication with the server that hosts the file.
  • Several QuickBooks Database service versions are another common cause of this error code.
  • Users modifying the system’s name on which they’ve hosted the company file is another cause.

A POINT TO NOTE: You can access the QuickBooks company file from QuickBooks Desktop. If you attempt to open it via Windows Explorer, then you will definitely encounter the error code 6123.

Also Read : QuickBooks update error 404


How to Fix the QuickBooks Error 6123 

There are various methods to resolve QuickBooks error 6123,0. You can find detailed explanations of all of these methods below. Use them according to your specific situation. 


1. Resolve Error 6123 when Opening, Upgrading or Retrieving the Company File

In such a case, you should first install the QuickBooks Tools Hub and run the Quick Fix My Program in it, followed by the File Doctor. Here are the steps to carry out these processes.


2. Install QuickBooks Tools Hub

This utility resolves various errors like 6123. You can use it on Windows 10, 64-bit by following these steps.

  • Firstly, download the latest version of the Tool Hub on your Windows desktop.
  • Open the downloaded ‘QuickBooksToolHub.exe’ file.
  • Adhere to the steps on your screen to install the utility.
  • Double-tap the icon of Tools Hub after it installs.


3. Run Quick Fix My Program

The next step is to run the Quick Fix My Program tool in the Tools Hub. Choose ‘Program Problems‘ in the utility and follow these points.

  • Choose ‘Quick Fix My Program.’ In about a minute, it will finish running and fixing your problem.
  • Now launch QuickBooks and see if the error message is still there.


4. Run the File Doctor Tool

You should run the File Doctor Tool if the above two steps did not troubleshoot error code 6123. This tool will scan and fix data issues.

  • Choose ‘Company File Issues‘ in the Tools Hub.
  • Opt for ‘Run QuickBooks File Doctor.’
  • Select your company file when the File Doctor opens.
  • Pick ‘Check your file‘ followed by ‘Continue.’
  • The File Doctor Utility will repair your file.
  • Now your QuickBooks will open your company file without any issues.


5. Resolve Error 6123 when Restoring the Company File

You can restore the company file straight from the hard drive. Follow these steps to do so. 

  • If your file is present on an external or network storage device, shift the backup file to the local hard drive. 
  • Now, in QuickBooks, navigate to the ‘File‘ menu and choose ‘Open or Restore Company.’
  • Now, choose ‘Restore a backup copy‘ and hit ‘Next.’
  • Choose ‘Local Backup‘ followed by ‘Next.’
  • Browse your system for your backup company file. The file will be in this format: your company name.qbb
  • Choose a folder where you will save the file you’ve restored. 
  • Now, choose ‘Open.’
  • Lastly, choose ‘Save.’ 


6. Resolve Error 6123 When Restoring a Backup on Another System 

If you see QuickBooks error 6123 while restoring a backup on a new system, you can make a portable company file (.qbm). Then, use this file to restore your company file. 

  • Launch QB Desktop on the same system on which you made the backup company file. 
  • Launch your original company file and not the backup. 
  • Now, create a portable copy of your company file. For it, launch QuickBooks and sign in as an admin. 
  • Navigate to the ‘File‘ menu and choose ‘Create copy.’
  • Choose ‘Portable company file‘ followed by ‘Next.’
  • Give a unique name to your portable company file. 
  • Now, choose a location to save it. 
  • After that, select ‘Save,’ followed by ‘OK.’
  • Launch QB Desktop on the new system. 
  • Restore the company file through the portable copy. 


  1. Launch QuickBooks and sign in as an admin. 
  2. Navigate to the ‘File‘ menu and choose ‘Open or Restore Company.’
  3. Choose ‘Restore a portable file,’ followed by ‘Next.’
  4. Choose your portable company file. 
  5. Now, select ‘Open.’
  6. Go through the notes present on the ‘Where do you want to restore the file‘ page and choose ‘Next.’
  7. Lastly, choose ‘Save.’


7. Run the QB Connection Diagnostic Tool

Another good way to fix QuickBooks error 6123 is by installing and running the QuickBooks Connection Diagnostic Tool. Follow these points to run the Tool. 

  • Firstly, check the network connection on your main computer. 
  • After that, install and run the Connection Diagnostic Tool. This tool will fix this specific error code on your system. 


8. Resolve the Damaged Data Files

If you find the methods above not resolving the error code 6123, go ahead and fix the damaged network data files. Here are the steps to follow.

  • Firstly, hit the Windows key or Start button.
  • After that, click ‘Explore.’
  • Now examine your company file. Then right-tap the file having .ND extension.
  • Lastly, just rename this file to .ndold


Although these steps will fix the QB error 6123, 0, you won’t find yourself able to shift to a multi-user mode. If you need to switch to this mode, you must perform the following steps.

  • Navigate to the ‘File‘ menu. 
  • After that, opt for ‘Utilities.’
  • Now host the multi-user access.
  • Head over to ‘File‘ and switch to this mode.


A POINT TO NOTE: If you cannot open the company file due to any reason, the option of ‘Switch to multi-user mode‘ won’t be there. In such a scenario, always navigate to ‘File‘ followed by ‘Utilities‘ and from there, host multi-user access.

Also Read : Quickbooks unrecoverable error

Final Thoughts

The resolutions outlined in this post are all quite effective in resolving QuickBooks error 6123. You will be able to access your company file and work without interruption. However, if you cannot tackle the error by following these instructions or need additional help, talk to expert QuickBooks technical support services.