info: [debug] executing cmd: D:\software\adt-bundle-windows-x86_64\sdk\platform-tools\adb.exe -s fdd3bacc shell "echo 'ping'"
error: UiAutomator quit before it successfully launched
error: Failed to start an Appium session, err was: Error: UiAutomator quit before it successfully launched
info: [debug] Cleaning up android objects
info: [debug] Cleaning up appium session
info: [debug] Error: UiAutomator quit before it successfully launched
at null. (D:\software\python\Appium\node_modules\appium\lib\devices\android\android.js:204:23)
at Object.async.eachSeries (D:\software\python\Appium\node_modules\appium\node_modules\async\lib\async.js:145:20)
at androidHybrid.stopChromedriverProxies (D:\software\python\Appium\node_modules\appium\lib\devices\android\android-hybrid.js:234:9)
at null. (D:\software\python\Appium\node_modules\appium\lib\devices\android\android.js:199:10)
at null. (D:\software\python\Appium\node_modules\appium\lib\devices\android\android.js:221:9)
at androidCommon.uninstallApp (D:\software\python\Appium\node_modules\appium\lib\devices\android\android-common.js:479:5)
at null. (D:\software\python\Appium\node_modules\appium\lib\devices\android\android.js:219:12)
at null. (D:\software\python\Appium\node_modules\appium\lib\devices\android\android.js:228:11)
at D:\software\python\Appium\node_modules\appium\node_modules\appium-adb\lib\adb.js:890:7
at null. (D:\software\python\Appium\node_modules\appium\node_modules\appium-adb\lib\adb.js:172:9)

搜索了一下站内，也有同学遇到过这个问题：
http://testerhome.com/topics/715
但其解决办法，删除 AppiumBootstrap.jar，不过后面跑测试用例又报错了：
info: [debug] Error: Could not find AppiumBootstrap.jar; please run 'grunt buildAndroidBootstrap'
at null. (D:\software\python\Appium\node_modules\appium\lib\devices\android\android.js:358:10)
at Object.oncomplete (fs.js:107:15)
info: [debug] Responding to client with error: {"status":33,"value":{"message":"A new session could not be created. (Original error: Could not find AppiumBootstrap.jar; please run 'grunt buildAndroidBootstrap')","origValue":"Could not find AppiumBootstrap.jar; please run 'grunt buildAndroidBootstrap'"},"sessionId":null}

求各位大神指点。