Oracle SQL Developer: Failure - Test failed: The Network Adapter could not establish the connection?

Question

Problem

Please note that I changed details for security purposes. However, the problem remains intact.

I installed an Oracle 11g database on a server at l

Answer 1

I solved just by: given correct host and port so:

1. Open oracle net manager
2. Local
3. Listener

in Listener on address 2 then copy host to Oracle Developer

finally connect to oracle