Hello All,
I am facing a strange issue today.
I installed 11g xe db in windows(64) environment 2 yrs ago. It's working correctly. Suddenly I am facing to connect the database through SQL Developer.
Below error id given when I tried to connect the database.
Listener refused the connection with following error.ORA-12505 TNS:listener does not currently known of SID given in connect descriptor.
Strange thing is:
I am able to connect the database by default SQL Plus coming with XE DB.
Can anyone plz help me to resolve the issue. What's wrong when try to connect through sql developer.?

Thanks,
Tanmoy