Several reasons trigger QuickBooks error code 12029 and the most troublesome of them all is an incorrect browser or security settings and misconfigured antivirus or firewall program. You can eliminate QuickBooks error 12029 by verifying the internet explorer settings and rectify them if needed. For that, open Internet Explorer, click Tools and go to internet options. Now, click the Security tab, click the globe icon, and ensure that the security level is set at medium-high. Now click the Connections tab, hit Never dial a connection, and click ok. Under LAN settings make sure the automatically detect settings is chosen and verify that use a proxy server checkbox is clear. Once done click ok, close Internet Explorer and reboot your system.