I can use dsa.msc correctly ( Active Directory User and computer :  create user account , update) , but @ server manager , it just simplify do not allow me to run "dsac.exe" (Active Directory Administrative Center)...help.

Does that help: https://social.technet.microsoft.com/Forums/itmanagement/en-US/ece9bcc2-1a33-461e-a69d-bb4cabf65994/active-directory-administrative-center-must-close-due-to-an-unknown-error?forum=winservergen

Hi,

Any software did you installed on the server?

Did you install any update recently?

So did you try to open the ADAC using server manager gui?

Please check if the Active Directory Web services is running or not.

Regards.

Hi,

Any update about the issue?

Please feel free to let us know if you need further assistance.

Regards.