When trying to enter your credentials to run a Box migration or import action, the following error is shown:
The user with the login 'login_name' could not be found in the Box enterprise. Please make sure that you are properly connected and that the requested user exists.
This error occurs when Sharegate is unable to retrieve the user credentials from Box.
You need to run connect-box again to ensure you are properly connected.
If this does not work, please validate that the credentials you are using are correct.