Azure AD Sign-in Error 50001

Error 50001-The service principal name was not found in this tenant. This can happen if the application has not been installed by the administrator of the tenant. The resource principal was not found in the directory or is invalid.

About Azure Activity sign-in activity reports:

Azure Active Directory's reporting tool generates 'Sign-in activity' reports that give you insight on who 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:

The service principal name could not be found since the application was not installed by the administrator of the tenant. Hence, the resource principal found in the directory is invalid.

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