QuickBooks Connection Has Been Lost -Troubleshooting Guide A common error that arises when QuickBooks loses contact with the company file is QuickBooks Connection Has Been Lost. Incorrect settings, server problems, or network problems may be the cause of this. Verifying firewall settings, network connections, and the accessibility of the file's hosting server are necessary to fix it. For expert QuickBooks phone support, call 1.855.738.2784. URL:https://www.bizmakersamerica.org/blog/preventive-measures-for-quickbooks-connection-has-been-lost-issue