ORA-00030: User session ID does not exist

Error:
ORA-00030: User session ID does not exist.

SQL> ALTER SYSTEM KILL SESSION '690,3411';
ALTER SYSTEM KILL SESSION '690,3411'
*
ERROR at line 1:
ORA-00030: User session ID does not exist.


Cause:
User id is not exist in connected session. May user disconnect or you provide the wrong SID.

Solution:
1. Check the V$SESSION view for the correct SID and SERIAL#

col username for a10
col action for a15
SELECT Username,SID,SERIAL#,STATUS,action from v$session where username is not null;

USERNAME          SID    SERIAL# STATUS   ACTION
---------- ---------- ---------- -------- ---------------
SYS               102      21507 ACTIVE
HR                302      55774 INACTIVE
SYS               396      44946 INACTIVE

2. Proper syntax for the SID and SERIAL#

ALTER SYSTEM KILL SESSION 'sid,serial#' immediate;

--Kill the correct SID,SERIAL# present in V$SESSION
SQL> ALTER SYSTEM KILL SESSION '302,55774' immediate;
System altered.