QuickBooks Error Code 6123 is a common issue that users encounter while attempting to open or access a company file. This error typically occurs when QuickBooks is unable to establish a connection with the company file, often resulting in an error message such as "QuickBooks Error 6123: An error occurred while QuickBooks tried to connect to your company file." It can be caused by a variety of reasons, including network issues, corrupted files, damaged installation, or problems with the server hosting the company file. Below are some troubleshooting steps to fix this error.