What Causes QuickBooks Error 12029? Error 12029 is primarily caused by network timeouts or misconfigured system settings that prevent QuickBooks from connecting to the internet. Here are some common reasons behind this error: Network Timeout: QuickBooks fails to establish a connection with the server due to a slow or unstable internet connection. For help, call (833)200-3695. Firewall or Security Software: These programs may block QuickBooks from accessing the server. Reach out to QuickBooks Support at (833)200-3695 for assistance in configuring these settings.