I’m using ORACLE SQL DEVELOPER software,
i write queries into ORACLE SQL DEVELOPER worksheet

Error I’m getting is:

An error was encountered performing the requested operation:

Listener refused the connection with the following error:
ORA-12505, TNS:listener does not currently know of SID given in connect descriptor
  (CONNECTION_ID=uLcKF/XDSrqt/eprG9uV1g==)

Vendor code 12505

listener.ora

DEFAULT_SERVICE_LISTENER = XE

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = CLRExtProc)
      (ORACLE_HOME = C:softwareoracle21cdbhomeXE)
      (PROGRAM = extproc)
      (ENVS = "EXTPROC_DLLS=ONLY:C:softwareoracle21cdbhomeXEbinoraclr.dll")
    )
  )

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
    )
  )

tnsnames.ora

XE =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = XE)
    )
  )

LISTENER_XE =
  (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))


ORACLR_CONNECTION_DATA =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
    )
    (CONNECT_DATA =
      (SID = CLRExtProc)
      (PRESENTATION = RO)
    )
  )

These are my connection properties.

Some things that i tried:

1. Checked both network files (listener.ora and tnsnames.ora) also changed Host = localhost in tnsnames.ora file because i think if i set it to localhost i do not have to worry about my ip address getting changed(Maybe it is related to ip address that’s why i am getting this error).

2. checked on stackoverflow too but it didn’t helped me.