Methods to fix QuickBooks error 3371 are as:

The two error dialog box displays two different solution procedure to follow. One says about re-installing your product and another suggest to search for help on the website. The both option seems not to be efficient. Hence, here on we are describing how to fix this particular problem.

  • Press window key + R on your keyboard.
  • After that, a window will open. Enter (or copy and paste) here C:\ProgramData\Intuit\Entitlement Client\v8
  • You will reach window explorer at following location
  • Just delete this ecml file. Do right click and select delete. Close the window now.
  • After performing this step, Run QuickBooks, Register the product again.
  • Most probably, you will be able to resolve your issues.

source article:http://www.askproadvisor.com/question/how-to-fix-quickbooks-error-code-3371/