title: Error- pl/sql developer -12154 tns could not resolve the connect identifier specified
body: <p>Good Morning. I tell you my connection problem with pl / sql Developer.</p>
  <p>First, I will indicate my environment:
  -SO Windows10 64 bits.
  -PLSQL Developer 13 (64 bit)
  -Client Oracle 12-64bits.</p>
  <p>Now I put the screenshots of my settings.</p>
  <p><img src="https://i.stack.imgur.com/nYBmK.jpg" alt="preferences connection" /></p>
  <p><img src="https://i.stack.imgur.com/XcPcL.jpg" alt="enter image description here" /></p>
  <p><img src="https://i.stack.imgur.com/PMnJM.jpg" alt="system file directory" /></p>
  <p><img src="https://i.stack.imgur.com/VHhBl.jpg" alt="enter image description here" /></p>
  <p><img src="https://i.stack.imgur.com/4rKGQ.jpg" alt="When I want to connect Pl / SQl developer finds the file now because I get my connection name: 'exadata'" /></p>
  <p>But finally the connection error message returns</p>
  <p><img src="https://i.stack.imgur.com/UBFDi.jpg" alt="enter image description here" /></p>