Part B FreeFall Error Tutorial

Hi everyone, When I followed the instructions in the tutorial, this error appeared with the BT connection
"E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.pruebadeconeccion, PID: 7252
java.lang.BootstrapMethodError: Exception from call site #1 bootstrap method
at com.mbientlab.metawear.android.BtleService$AndroidPlatform.connectAsync(BtleService.java:475)
at com.mbientlab.metawear.impl.JseMetaWearBoard.connectAsync(JseMetaWearBoard.java:752)
at com.example.pruebadeconeccion.MainActivity.retrieveBoard(MainActivity.java:61)
at com.example.pruebadeconeccion.MainActivity.onServiceConnected(MainActivity.java:44)
at android.app.LoadedApk$ServiceDispatcher.doConnected(LoadedApk.java:1848)
at android.app.LoadedApk$ServiceDispatcher$RunConnection.run(LoadedApk.java:1880)
at android.os.Handler.handleCallback(Handler.java:873)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:214)
at android.app.ActivityThread.main(ActivityThread.java:7091)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:975)
Caused by: java.lang.ClassCastException: Bootstrap method returned null
at com.mbientlab.metawear.android.BtleService$AndroidPlatform.connectAsync(BtleService.java:475) 
at com.mbientlab.metawear.impl.JseMetaWearBoard.connectAsync(JseMetaWearBoard.java:752) 
at com.example.pruebadeconeccion.MainActivity.retrieveBoard(MainActivity.java:61) 
at com.example.pruebadeconeccion.MainActivity.onServiceConnected(MainActivity.java:44) 
at android.app.LoadedApk$ServiceDispatcher.doConnected(LoadedApk.java:1848) 
at android.app.LoadedApk$ServiceDispatcher$RunConnection.run(LoadedApk.java:1880) 
at android.os.Handler.handleCallback(Handler.java:873) 
at android.os.Handler.dispatchMessage(Handler.java:99) 
at android.os.Looper.loop(Looper.java:214) 
at android.app.ActivityThread.main(ActivityThread.java:7091) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:975) "