1. I am using appium version 1.3.7.
2. I have connected physical device via usb.
3. I have launched appium server,after a while appium get crashed.
4. I have pasted that full log below.
5. I have attached the screen shot below.

![enter image description here](https://i.stack.imgur.com/3ofKY.png) 

```
Launching Appium with command: '/Applications/Appium.app/Contents/Resources/node/bin/node' lib/server/main.js --command-timeout "7200" --pre-launch --platform-version "8.1" --platform-name "iOS" --app "/Users/al/work/sample.app" --udid "f5de3fd5ccded92e40e86c652ce2a6f9414fe1a0" --device-name "iPhone 4s"

info: [debug] Starting Appium in pre-launch mode

info: Pre-launching app

info: [debug] Using local app from command line: /Users//al/work/sample.app
info: [debug] Creating new appium session 1cdc5dc0-36d2-40b9-922b-33601f28846b

info: [debug] Removing any remaining instruments sockets

info: [debug] Cleaned up instruments socket /tmp/instruments_sock
info: [debug] Setting Xcode folder

info: [debug] Setting Xcode version

info: [debug] Setting iOS SDK Version

info: [debug] Getting sdk version from xcrun with a timeout

info: [debug] iOS SDK Version set to 8.1

info: [debug] Not checking whether simulator is available since we're on a real device
info: [debug] Detecting automation tracetemplate

info: [debug] Not auto-detecting udid, running on sim

info: [debug] Parsed app Info.plist (as binary)

info: [debug] Parsed app Localizable.strings
info: [debug] Getting bundle ID from app

info: [debug] Parsed app Info.plist (as binary)

info: [debug] Creating instruments
info: On some xcode 6 platforms, instruments-without-delay does not work. If you experience this, you will need to re-run appium with the --native-instruments-lib flag
info: [debug] Preparing uiauto bootstrap
info: [debug] Dynamic bootstrap dir: /Users/alk/Library/Application Support/appium/bootstrap
info: [debug] Dynamic env: {"nodePath":"/Applications/Appium.app/Contents/Resources/node/bin/node","commandProxyClientPath":"/Applications/Appium.app/Contents/Resources/node_modules/appium/node_modules/appium-uiauto/bin/command-proxy-client.js","instrumentsSock":"/tmp/instruments_sock","interKeyDelay":null,"justLoopInfinitely":false,"autoAcceptAlerts":false,"autoDismissAlerts":false,"sendKeyStrategy":"grouped"}

info: [debug] Dynamic bootstrap code: // This file is automatically generated. Do not manually modify!
...
info: [debug] Dynamic bootstrap path: /Users/alk/Library/Application Support/appium/bootstrap/bootstrap-d5a0fb924946d8d3.js

info: [debug] Reusing dynamic bootstrap: /Users/alk/Library/Application Support/appium/bootstrap/bootstrap-d5a0fb924946d8d3.js
info: [debug] Getting device string from opts: {"forceIphone":false,"forceIpad":false,"xcodeVersion":"6.1.1","iOSSDKVersion":"8.1","deviceName":"iPhone 4s","platformVersion":"8.1"}
info: [debug] fixDevice is on
info: [debug] Final device string is: 'iPhone 4s (8.1 Simulator)'
info: [debug] Not setting device type since we're on a real device
info: [debug] Checking whether we need to set app preferences

info: [debug] Not setting iOS and app preferences since we're on a real device
info: [debug] Running ios sim reset flow
info: [debug] Killing the simulator process
info: [debug] Killall iOS Simulator

info: [debug] Killing any other simulator daemons

info: [debug] On a real device; cannot clean device state
info: [debug] Not setting locale because we're using a real device
info: [debug] No iOS / app preferences to set

info: [debug] Starting iOS device log capture via deviceconsole

info: [debug] Not pre-launching simulator

info: [debug] Creating iDevice object with udid f5de3fd5ccded92e40e86c652ce2a6f9414ee1a2

info: [debug] Checking app install status using: /Applications/Appium.app/Contents/Resources/node_modules/appium/build/fruitstrap/fruitstrap isInstalled --id f5de3fd5ccded92e40e86c652ce2a6f9414ee1a2 --bundle com.vr.iphone.sample

info: [debug] App is not installed. Will try to install the app.

info: [debug] Installing app using cmd: /Applications/Appium.app/Contents/Resources/node_modules/appium/build/fruitstrap/fruitstrap install --id f5de3fd5ccded92e40e86c652ce2a6f9414ee1a2 --bundle "/Users/al/work/sample.app

info: [debug] Cleaning up appium session

error: Could not pre-launch appium: Error: Unable to install [/Users/al/work/sample.app] to device with id [f5de3fd5ccded92e40e86c652ce2a6f9414ee1a2]. Error [Error: Command failed: /bin/sh -c /Applications/Appium.app/Contents/Resources/node_modules/appium/build/fruitstrap/fruitstrap install --id f5de3fd5ccded92e40e86c652ce2a6f9414ee1a2 --bundle "/Users/al/work/sample.app"
Assertion failed: (AMDeviceStartService(device, CFSTR("com.apple.afc"), &afcFd, NULL) == 0), function handle_device, file fruitstrap.c, line 523.
]

```