QuickBooks Error 6000 occurs when the company file is corrupted or when you try to open it. Several errors are associated with it in the form of the codes. The different codes associated with the QuickBooks 6000 series error are 6000 83, 6000 80, 6000 77, 6000 301, and 6000 832. One reason would be the firewall of the antivirus must be blocking the internet. The. The TLG file must be corrupted. The internet connection or the network connection must’ve got disconnected. The configuration of the network must not be configured properly. There may be multiple users trying to use the same company file. The problem may also occur when you try to take a backup of your files. The company file, which is a part of the QuickBooks, must’ve got corrupted.