Javascript 无法在ionic上启动活动ComponentInfo{io.ionic.starter/io.ionic.starter.MainActivity}

我正在开发一款ionic应用程序，我想在安卓4设备上运行它。当我尝试构建apk，并在android studio上运行它时，我得到了这个错误

java.lang.RuntimeException: Unable to start activity ComponentInfo{io.ionic.starter/io.ionic.starter.MainActivity}: java.lang.RuntimeException: Failed to create webview. 
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
        at android.app.ActivityThread.access$600(ActivityThread.java:123)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:137)
        at android.app.ActivityThread.main(ActivityThread.java:4424)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:511)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
        at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.RuntimeException: Failed to create webview. 
        at org.apache.cordova.CordovaWebViewImpl.createEngine(CordovaWebViewImpl.java:82)
        at org.apache.cordova.CordovaActivity.makeWebViewEngine(CordovaActivity.java:206)
        at org.apache.cordova.CordovaActivity.makeWebView(CordovaActivity.java:202)
        at org.apache.cordova.CordovaActivity.init(CordovaActivity.java:146)
        at org.apache.cordova.CordovaActivity.loadUrl(CordovaActivity.java:224)
        at io.ionic.starter.MainActivity.onCreate(MainActivity.java:39)
        at android.app.Activity.performCreate(Activity.java:4466)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981) 
        at android.app.ActivityThread.access$600(ActivityThread.java:123) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147) 
        at android.os.Handler.dispatchMessage(Handler.java:99) 
        at android.os.Looper.loop(Looper.java:137) 
        at android.app.ActivityThread.main(ActivityThread.java:4424) 
        at java.lang.reflect.Method.invokeNative(Native Method) 
        at java.lang.reflect.Method.invoke(Method.java:511) 
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) 
        at dalvik.system.NativeStart.main(Native Method) 
     Caused by: java.lang.reflect.InvocationTargetException

我已经检查了proguard文件，它包含规则

-keep class com.ionicframework.cordova.webview.** {*; }
-keep class com.ionicframework.cordova.webview.*

我不知道为什么会出现这个错误。我更新了爱奥尼亚版本，还有科尔多瓦。而且仍然出现