QuickBooks Error Code 6123 pops up at the time of accessing the QB company files or upgrading the QuickBooks software. Reasons behind QuickBooks Error 6123 Mentioned-below is a list of all the possible reasons that can lead to the error 6123 QuickBooks: 1. Damaged company files may cause to the error 6123. 2. Due to incorrect firewall settings. 3. You may face the error because of the change in the PC name. Solutions to fix QuickBooks Error 6123 Undergo the following solutions in order to get rid of QuickBooks error code 6123. We have tried to provide you all the fixes for the same error: Solution 1: We first advise you to use the QuickBooks file doctor tool. The tool will surely troubleshoot the error 6123. Solution 2: Remove all the special characters from the name of company files. Solution 3: You can also use the QuickBooks Tools hub to get rid of the QuickBooks Error 6123. Solutions 4: Restore the company file backup. To Conclude Even after, applying the above-mentioned solutions for QuickBooks Error 6123, you are still confronting the error. Then, we recommend you to connect with us to get more solutions in detail to fix your issues. For this, you just need to dial our QuickBooks Premier Support Phone Number 1-888-660-0607.