title: ORA 12505 error for SQL Developer
body: <p>I have recently ran into a problem when trying to connect to my Database. The error is stating that it cant find the listener.</p>
  
  <pre><code>Status : Failure -Test failed: Listener refused the connection with the following error:
  ORA-12505, TNS:listener does not currently know of SID given in connect descriptor
  </code></pre>
  
  <p>I read to post whats in the listener.ora and tnsnames.ora but when I try to open these files via windows explorer it tells me to choose a program to open it with, and then it doesnt open.</p>
  
  <p>Can someone help me with this problem so I can get back to practicing coding please?</p>