Error Description:

Msg 17549, Level 16, State 1:
Server 'SYB_ASE', Procedure 'sp_dropuser', Line 3:
You cannot drop user because user 'testuser' owns grantable privileges and granted them to other users. The user has granted the following privileges:

Resolution:

Step1: First find out uid of user

1> select uid from sysusers where suid = suser_id('testuser')
2> go
uid=220

Step2: Updating Sysprotects

1>update sysprotects set grantor =1 where grantor=220
2>go

Step3: Drop User

1> sp_dropuser testuser
2> go
User has been dropped from current database.
(return status = 0)
1> exit