Navigate to admin/settings.php?section=manageauths and enable OAuth 2 authentication plugin. Configure Microsoft OAuth2 service as described here https://docs.moodle.org/310/en/OAuth_2_Microsoft_service Log out. Head to https://account.microsoft.com/account  and log into your account. Click on the Privacy tab at the top of the page. You may need to verify your identity via an email code. Scroll down to the Other privacy settings section. Go to Apps and services > Apps and services that can access your data. Review the list of apps and establish which you want to revoke. Click on Edit below the corresponding app's name. Select Remove these permissions. Navigate to your moodle login page. Click on Microsoft button. Enter your email address and password. When account.live.com asks for your confirmation of logging click No: Confirm , that login page is displayed. Confirm , that "The user has denied access to the scope requested by the client application." error is displayed.