Appium_ios_ app crashes everytime. In simulator as well in real device

nfo: [debug] [INST STDERR] 2016-02-12 11:20:34.648 instruments[5448:43171] Attempting to change event horizon while disengage

info: [debug] [INST STDERR] Instruments Trace Error : Target failed to run: Failed looking up pid of launched process
info: [debug] [INST STDERR] 2016-02-12 11:20:34.650 instruments[5448:43235] Attempting to change event horizon while disengage

info: [debug] [INSTSERVER] Instruments exited with code 253
info: [debug] Killall instruments
info: [debug] Instruments crashed on startup
info: [debug] We exceeded the number of retries allowed for instruments to successfully start; failing launch
info: [debug] Stopping iOS log capture
info: [debug] Reset not set, not ending sim or cleaning up app state
info: [debug] Cleaning up appium session
info: [debug] Error: Instruments crashed on startup
at [object Object].Instruments.onInstrumentsExit (/Users/user/Downloads/
at [object Object]. (/Users/user/Downloads/
at ChildProcess.emit (events.js:110:17)
at Process.ChildProcess._handle.onexit (child_process.js:1074:12)
info: [debug] Responding to client with error: {“status”:33,“value”:{“message”:“A new session could not be created. (Original error: Instruments crashed on startup)”,“origValue”:“Instruments crashed on startup”},“sessionId”:null}
info: <-- POST /wd/hub/session 500 77690.305 ms - 182

error: Failed to start an Appium session, err was: Error: Instruments crashed on startup

Could you provide more info such as

type of app,osx version ,device version,full appium log.