I have a .NET Core 2 app template that is configured to use Azure AD out of the box.
The configuration is:
{
\"AzureAd\": {
\"Instance\": \"https:
I had a similar problem with a .NET 4.6.1 web application. I had to configure the Reply URL for my app in azure similar to the accepted answer, however the callback url was different.
Select Azure Active Directory -> App Registrations -> <your app>
Select Settings -> Reply URLs
Add your apps URL + '/.auth/login/aad/callback'
For Example:
https://somesite.azurewebsites.net/.auth/login/aad/callback
If you are signing in from AAD you should use app-base-url/sigin-aad.