Azure AD Sign-in Error 65001

Error 65001 - Application X doesn't have permission to access application Y or the permission has been revoked. Or The user or administrator has not consented to use the application with ID X. Send an interactive authorization request for this user and resource. Or The user or administrator has not consented to use the application with ID X. Send an authorization request to your tenant admin to act on behalf of the application : Y for Resource : Z.

About Azure Activity sign-in activity reports:

Azure Active Directory's (renamed as Entra ID) reporting tool generates 'Sign-in activity' reports that give you insights on who has performed the tasks that are enlisted in the Audit logs.

• All Sign-in activity reports can be found under the Activity section of Azure Active Directory.
• The default list view of Audit logs can be customized by adding additional fields.
• The reports can also be filtered to let you view only the activities that are relevant. 
• Here is an example of how a sign-in activity report looks like:

  

Error description:

Application X doesn't have permission to access application Y or the permission has been revoked.

Cause 1:The user or administrator has not consented to use the application with ID X.

Solution:Send an interactive authorization request for this user and resource.

Cause 2:The user or administrator has not consented to use the application with ID X.

Solution:Send an authorization request to your tenant admin to act on behalf of the application : Y for resource : Z.

Auditing Azure AD environments with ADAudit Plus:

ADAudit Plus offers change monitoring for your Azure AD environment with the following features:

• Correlated view across hybrid environments
• Real-time alerts
• Schedulable reports
• Autonomous change remediation
• Comprehensive search
• Out-of-the-box compliance reports