QuickBooks Error 3371 occurred when your QuickBooks fails to load the license-related essential File, and If we talk about what caused it, So the anti-virus does make this File corrupted, File by mistakenly moved. You can go through this article where we have written a comprehensive guide on How to resolve error 3371 in QuickBooks Desktop, and you can contact to our QuickBooks team via 855-856-0042 to get instant assistance.