当我尝试输入命令“cordova platform add android”时，我收到此错误：
创建android项目......
C:\Users\Andre\.cordova\lib\android\cordova\3.4.0\bin\node_modules\q\q.js:126
throw e;
^
Error: An error occurred while listing Android targets
at C:\Users\Andre\.cordova\lib\android\cordova\3.4.0\bin\lib\check_reqs.js:87:29
at _rejected (C:\Users\Andre\.cordova\lib\android\cordova\3.4.0\bin\node_modules\q\q.js:808:24)
at C:\Users\Andre\.cordova\lib\android\cordova\3.4.0\bin\node_modules\q\q.js:834:30
at Promise.when (C:\Users\Andre\.cordova\lib\android\cordova\3.4.0\bin\node_modules\q\q.js:1079:31)
at Promise.promise.promiseDispatch (C:\Users\Andre\.cordova\lib\android\cordova\3.4.0\bin\node_modules\q\q.js:752:41)
at C:\Users\Andre\.cordova\lib\android\cordova\3.4.0\bin\node_modules\q\q.js:574:44
at flush (C:\Users\Andre\.cordova\lib\android\cordova\3.4.0\bin\node_modules\q\q.js:108:17)
at process._tickCallback (node.js:415:13)
Error: cmd: Command failed with exit code 8
at ChildProcess.whenDone (C:\Users\Andre\AppData\Roaming\npm\node_modules\cordova\src\superspawn.js:112:23)
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)**
我做错了什么？