Azure AD connection logins fail with error: "This login.microsoftonline.com page can't be found"

Problem statement

We set up an Azure AD connection and enabled it but it is not working. Can you please investigate this and let us know if there’s something wrong with the setup?

Solution

Go to Dashboard > Authentication > Enterprise > Microsoft Azure AD > {connection name}

Under the Settings tab, please find the Microsoft Azure AD Domain, confirm it is correct, and remove the https:// and the trailing slash if there is one.