Deal with QuickBooks error code 6000 like a pro and fix it today! Often QB accounting software users report QuickBooks error 6000 while trying to open a company file. The most common reasons behind error 6000 are corrupted TLG file, improper QuickBooks installation, firewall blocking the connection, multiple users logged into the same file, and a network connection problem. To get rid of QuickBooks error code 6000 one must be ready with the backup of files and then re-configure the firewall or antivirus software. Sometimes taking a simple step of renaming the .ND and .TLG files also resolve error 6000. Do you want to learn more! Contact the experts today.