If you’ve just logged in and received the 401 Unauthorized error, it means that the credentials you entered were invalid for some reason. 401 Unauthorized error messages are often customized by each website, especially very large ones, so keep in mind that this error may present itself in more ways than these common ones:
401 UnauthorizedAuthorization RequiredHTTP Error 401 - Unauthorized
The 401 Unauthorized error displays inside the web browser window, just as web pages do. Like most errors like these, you can find them in all browsers that run on any operating system.
How to Fix the 401 Unauthorized Error
Other Ways You Might See 401 Errors
Web servers running Microsoft IIS might give more information about the 401 Unauthorized error, such as the following: If you don’t have credentials or have forgotten yours, follow the instructions provided on the website for setting up an account or resetting your password. A number of server-side HTTP status codes also exist, like the often-seen 500 Internal Server Error.