Failed to authenticate HTTPS connection. Conflicting certificates for localhost when using Visual Studio for Mac

Lately, I have been trying Visual Studio for Mac as this version of Visual Studio has evolved significantly. However, something I noticed is that since I don’t use it often, the local SSL certificates created by dotnet in the Mac get a bit screwy.

There is a possibility that you might end up with a conflicting certificate for localhost from creating or setting up applications in the past.

If you work with the Mac version of Visual Studio, and you ever get the following error, run the commands at the bottom to clean up the existing certificates for localhost and create new ones.

Failed to authenticate HTTPS connection. System.IO.IOException: Authentication failed because the remote party has closed the transport stream.

Open the terminal window, browse to your dotnet project and execute the following commands:

$dotnet dev-certs https --clean
$dotnet dev-certs https

Happy coding!