QuickBooks Error 80070057 occurs when your system fails to access company files, often due to issues like incorrect file permissions or a corrupt company file. To resolve this error, start by checking your system's firewall settings to ensure QuickBooks is allowed through. Next, run the QuickBooks File Doctor to repair any damaged files. If the error persists, try restoring a backup of your company file. In cases of severe corruption, consider seeking professional help. For effective troubleshooting, feel free to contact QB Data Service at +1-888-538-1314 for expert assistance.