After create sde user using SDE administration Add user tool (and Create Database User toolbox), the new created user cannot login sde. I had to grant db_owner to the sde user then it can login the sde. But grant db_owner violate the IT security policy. I checked the sde user account and it already has privileges: create table, create procedure, create view and view definition. My database is MS SQL server 2012 and SDE is 10.4.
