ORA-12518 Tns: Listener could not hand off client conenction

Solution 1 :

First of all check the status of oracle service from windows

1. click start

2. click run

3. write services.msc and click ok to run the services.

4. double click on OracleServiceORCL (Here ORCL is the OracleInstancename)

5. click start

Now try to connect to the database.

Solution 2 :

This problem also can occur if your server is running out of memory then you just need to swap the memory to disk.

To solve this problem set DIRECT_HANDOFF_TTC_LISTENER=OFF in the listener.ora in the following way

SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(GLOBAL_DBNAME = orcl)
(ORACLE_HOME = C:\oracle\product\10.2.0\db_1)
(SID_NAME = ORCL)
)
(SID_DESC =
(PROGRAM = extproc)
(SID_NAME = PLSExtProc)
(ORACLE_HOME = C:\oracle\product\10.2.0\db_1)
)
)

LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = arabswell.mshome.net)(PORT = 1521))
DIRECT_HANDOFF_TTC_LISTENER=OFF
)
)

and restart the listener

Now try to connect to the database.

Hope it will work.