VQ2 error messages as shown in the FAQS: http://forum.opencart.com/viewtopic.php?f=170&t=165657 should be observed by forum users when an Opencart upgrade is involved.
A highly suggested method when upgrading the Opencart platform would be to disable all XML files from VQMod Manager or by FTP before running the experimental upgrade. Once the upgrade completed, reactivate your XML files one-by-one and refresh the page on your store accordingly to see if error messages would appear afterwards. In addition, verify in the VQMod Manager tool if no error lines appears to ensure the stability of the new Opencart release.
The most generated errors being found on Opencart forum originates from contributed programming. The increased post counters are caused by redundancies of the same solutions that were already provided prior.