Database diagram support objects cannot be installed because this database does not have a valid owner. To continue, first use the Files page of the Database Properties dialog box or the ALTER AUTHORIZATION statement to set the database owner to a valid login, then add the database diagram support objects.

Cuando obtenemos este mensaje de error: "Database diagram support objects cannot be installed because this database does not have a valid owner. To continue, first use the Files page of the Database Properties dialog box or the ALTER AUTHORIZATION statement to set the database owner to a valid login, then add the database diagram support objects", nos da comunmente cuando restauramos una bd  o por incompatibilidad

La solucion rapida es la siguiente:







  EXEC sp_dbcmptlevel 'ERP', '90';
  
  ALTER AUTHORIZATION ON DATABASE::ERP TO TULOGIN




y solucionado 


Saludos