Hi Kartihk,

I also had this or a very similar issue when configuring microsoft login and auto-linking.

In my case, the context was logging into the back-office via Microsoft as someone who had no existing Umbraco User account (which with auto-linking enabled, generates a new Umbraco User with the signed in email address).

I ended up 'Logged In' to the back-office in the sense that I wasn't redirected to the login page and remained under the /umbraco path, but like you, saw various 401 errors and other than that an entirely blank page.

I found that these auto-generated Users defaulted to 'Is Approved' = No, so it would seem like I was logged in as an unapproved user and could therefore see nothing.

As a short term/manual remedy, I found I could just login as another (administrative) back-office user and mark the troublesome user account as 'Is Approved' = Yes, repeat the Microsoft sign-in and all would work as expected.

As I didn't want to have that manual step going forwards, I essentially added it programatically in the OnAutoLinking callback described here in the docs:

        // Optional callback
        OnAutoLinking = (autoLinkUser, loginInfo) =>
        {
            // You can customize the user before it's linked.
            // i.e. Modify the user's groups based on the Claims returned
            // in the externalLogin info
            autoLinkUser.IsApproved = true;
        }

Note: I could find no way to save the 'autoLinkUser' but it seems to persist anyway without me having to call a save/write, I guess a later stage of the process within core code commits this update to the users record/DB.