This sounds kind of crazy, but there was an issue with Internet Toolkit not being activated that caused the error list window to come up whenever LabVIEW was opened. Does this happen with every VI you open, and every time you open LabVIEW? Do you have any unactivated products in your license manager? You may need to uninstall the expired software if you do, specifically Internet Toolkit. Let me know if this was the case.