Azure AD Sign-in Error 70001

Error 70001 - The application named X was not found in the tenant named Y. This can happen if the application with identifier X has not been installed by the administrator of the tenant or consented to by any user in the tenant. You might have mis configured the Identifier value for the application or sent your authentication request to the wrong tenant

About Azure Activity sign-in activity reports:

Azure Active Directory's 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:

The application named X was not found in the tenant named Y. This can happen if the application with identifier X has not been installed by the administrator of the tenant or consented to by any user in the tenant. You might have misconfigured the identifier value for the application or sent your authentication request to the wrong tenant.

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