Note: This method applies to Outlook 2013 (some builds) and earlier versions of MS Outlook.

Change the “ Login network security” settings to “ Anonymous Authentication.”.

Now, type 1 in the value data box and click “ Ok.” Exit registry editor to finish the process.

In the DWORD Value, type “ AlwaysUseMSOAuthForAutoDiscover” and click “ Modify.”.Now, click “ Edit” in the menu tab and select “ New,” and then click “ DWORD Value.”.Find the appropriate registry path according to your Outlook version.Close MS Outlook and start Registry Editor by typing regedit.exe in the Run dialog box.You can create or change the registry key so that Outlook start using the new authentication method for web services, such as EWS and Autodiscover. Change the Registry for Modern Authentication.Go to “ Control panel,” select “ Credential Manager,” and clear any cached credentials. Try to remove and reset your account credentials.One of the simplest things you can do to solve this issue is by updating Office 365 and software to the latest version.Here we have mentioned some of the most effective ways: There are several methods to resolve this issue. Methods to Fix Outlook Credentials Prompt Issue So, how can this issue be resolved? In this article, we will tell you about all the possible methods to solve this error. One main reason behind this issue can be that the setting of Logon network security on the Microsoft Exchange dialog box is not set to Anonymous Authentication.

It frustrates the user much as he cannot even configure or access the cloud account in the Microsoft Outlook application at all due to this continuous prompt for credentials. It occurs mostly when the user is trying to access the cloud mailbox in the Outlook application after the Office 365 migration. Outlook must be online or connected to complete this action. The connection to Microsoft Exchange is unavailable.

Problems with office 365 outlook