On this page, you will find more information about the most common causes and most relevant solutions for the QuickBooks error '401'. This process will require you to re-authorize the connection between Finale Inventory and your QBO Company file, which will fix the problem. There might be invalid login information stored locally in your browser that's disrupting the login process and throwing the 401 error. This error code usually comes up with an error message stating “The remote server returned an error: QuickBooks unauthorized error 401. Request is unauthorized”.