MP Control Manager detected DMP is not responding to HTTP requests. The http status code and text is %1, %2.%12 Possible ...

%11MP Control Manager detected DMP is not responding to HTTP requests.  The http status code and text is %1, %2.%12

Possible cause: DMP encountered an error when connecting to SQL Server. 
Solution: Verify that the SQL server is properly configured to allow Device Management Point access.   If using a standard SQL security account, verify that the SQL Server is configured to allow standard SQL Security; or configure the Device Management Point to use an NT integrated security account, with appropriate access.   If using integrated security, verify the account used by the DMP to connect to the SQL server is a member of the SMS_SiteSystemToSQLConnection_ group on the SQL server, that the account is not locked out, and that the account password is not expired.  (In standard security, the default account is SMS_SQL_RX_.)

Possible cause:  The SQL server Service Principal Names (SPNs) are not registered correctly in Active Directory
Solution:  Ensure SQL server SPNs are correctly registered.  Review Q829868.

Possible cause: Internet Information Services (IIS) isn't configured to listen on the ports over which SMS is configured to communicate. 
Solution: Verify that the designated Web Site is configured to use the same ports which SMS is configured to use.

Possible cause: The designated Web Site is disabled in IIS. 
Solution: Verify that the designated Web Site is enabled, and functioning properly.

Possible cause: The SMS ISAPI Application Identity does not have the requisite logon privileges. 
Solution: Verify that the account that the SMS ISAPI is configured to run under has not been denied batch logon rights through group policy.

For more information, refer to Microsoft Knowledge Base article 838891.
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