I am getting Authentication failed error from SourceTree as well as when I try from Visual Studio 2019 or 2017
On SourceTree it shows following errors
Authentication failed
unable to get secret
unable to receive callback from OAuth service provider
Please try restrarting SourceTree
Failed to listen on prefix 'http://localhost:34106/' because it conflicts with an existing registration on the machine.
On the browser Microsoft Edge it shows the message:
localhost sent an invalid response.