It would be my pleasure to help answer any questions you may have about the Error code 3371.
There are several reasons why you encounter this error code when you activate or open QuickBooks Desktop. You'll need to make sure you're using a supported license version which is compatible with the operating system.
Currently, add-on services work with the 2016 version and up. For more information, you can check the article below about the service discontinuation:
We can perform some basic troubleshooting to continue using QuickBooks Desktop. Please follow the steps in the order shown to fix the error:
Please be sure to let me know if there's anything else I can do for you by posting a response below. The Community is here for you.