Failed to start an Appium Session

Appium Server - 1.3.1
java client - 2.0.0
Real iPhone 4s device

Here is the log :

info: Client User-Agent string: Apache-HttpClient/4.3.3 (java 1.5)
info: [debug] App is an iOS bundle, will attempt to run as pre-existing
info: [debug] Creating new appium session d8c173d4-cc99-4779-9904-cb06439d602d
info: [debug] Removing any remaining instruments sockets
info: [debug] Cleaning up appium session
error: Failed to start an Appium session, err was: Error: EACCES, unlink ‘/tmp/instruments_sock’
info: [debug] Error: EACCES, unlink ‘/tmp/instruments_sock’
info: [debug] Responding to client with error: {“status”:33,“value”:{“message”:“A new session could not be created. (Original error: EACCES, unlink ‘/tmp/instruments_sock’)”,“errno”:3,“code”:“EACCES”,“path”:"/tmp/instruments_sock",“origValue”:“EACCES, unlink ‘/tmp/instruments_sock’”},“sessionId”:null}
info: <-- POST /wd/hub/session 500 10.461 ms - 255

I have already tried sudo rm -rf /tmp/instruments_sock