Appium Command failed: protocol failure；求解
出现了一个奇怪的问题，我用小米手机（4.4.4 版本）运行成功了，使用三星的手机（4.4.2 版本）就出现了下面的问题
info: [debug] Logcat terminated with code 0, signal null
info: [debug] Stopping logcat capture
info: [debug] Logcat already stopped
info: [debug] Sent shutdown command, waiting for UiAutomator to stop...
warn: UiAutomator did not shut down fast enough, calling it gone
error: Failed to start an Appium session, err was: Error: Command failed: protocol failureinfo: [debug] Cleaning up android objects
info: [debug] Cleaning up appium session
info: [debug] Error: Command failed: protocol failureat ChildProcess.exithandler (child_process.js:637:15)
at ChildProcess.EventEmitter.emit (events.js:98:17)
at maybeClose (child_process.js:743:16)
at Process.ChildProcess._handle.onexit (child_process.js:810:5)
info: [debug] Responding to client with error: {"status":33,"value":{"message":"A new session could not be created. (Original error: Command failed: protocol failure\r\n)","killed":false,"code":1,"signal":null,"origValue":"Command failed: protocol failure\r\n"},"sessionId":null}
info: <-- POST /wd/hub/session 500 32052.382 ms - 232
google 了一下，找到如下可能的解决方案：
http://stackoverflow.com/questions/15492406/getting-protocol-failure-error-while-installing-apk-using-adb-command-in-android
http://stackoverflow.com/questions/16554627/adb-protocol-failure-using-install-and-push
你都试试吧。
下次发询问帖麻烦说一下自己曾经找过什么解决方案，尝试后结果如何，以及自己的一些分析。
否则我只能根据 log 搬运 google 结果。。。因为我除了你给的 log 什么都不知道。。。
#1 楼 @chenhengjie123 你太不容易了
I found out that in my workplace the people who were facing this problem have only read permission on their computer USB port has and not write permission. After getting USB write permission from admin the problem is no longer occurring.
这个原因？
另外，三星的支持另外一种系统模式，是 5.0.0 的前版，不知道这个跟你有没有关系