[Cordova] Build failed

Hey guys,
I’m trying to compile my Meteor Cordova project with the current version of PhoneRTC . Now I’m getting everytime the following error:

[javac] warning: org/webrtc/AudioSource.class(org/webrtc:AudioSource.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/AudioTrack.class(org/webrtc:AudioTrack.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/MediaConstraints.class(org/webrtc:MediaConstraints.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/PeerConnectionFactory.class(org/webrtc:PeerConnectionFactory.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/VideoCapturer.class(org/webrtc:VideoCapturer.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/VideoRenderer.class(org/webrtc:VideoRenderer.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/VideoRendererGui.class(org/webrtc:VideoRendererGui.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/VideoSource.class(org/webrtc:VideoSource.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/VideoTrack.class(org/webrtc:VideoTrack.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/DataChannel.class(org/webrtc:DataChannel.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/IceCandidate.class(org/webrtc:IceCandidate.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/MediaStream.class(org/webrtc:MediaStream.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/PeerConnection.class(org/webrtc:PeerConnection.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/SdpObserver.class(org/webrtc:SdpObserver.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/SessionDescription.class(org/webrtc:SessionDescription.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/PeerConnection$IceConnectionState.class(org/webrtc:PeerConnection$IceConnectionState.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/PeerConnection$IceGatheringState.class(org/webrtc:PeerConnection$IceGatheringState.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/PeerConnection$Observer.class(org/webrtc:PeerConnection$Observer.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/PeerConnection$SignalingState.class(org/webrtc:PeerConnection$SignalingState.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/MediaStreamTrack.class(org/webrtc:MediaStreamTrack.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] /Users/dennis/Desktop/Entwicklung/twyce/app/.meteor/local/cordova-build/platforms/android/src/com/dooble/phonertc/PhoneRTCPlugin.java:316: cannot find symbol
[javac] symbol : method getView()
[javac] location: class org.apache.cordova.CordovaWebView
[javac] ((WebView) webView.getView()).addView(_videoView, _videoParams);
[javac] ^
[javac] /Users/dennis/Desktop/Entwicklung/twyce/app/.meteor/local/cordova-build/platforms/android/src/com/dooble/phonertc/PhoneRTCPlugin.java:336: cannot find symbol
[javac] symbol : method getView()
[javac] location: class org.apache.cordova.CordovaWebView
[javac] ((WebView) webView.getView()).removeView(_videoView);
[javac] ^
[javac] warning: org/webrtc/VideoRendererGui$ScalingType.class(org/webrtc:VideoRendererGui$ScalingType.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/VideoRendererGui$YuvImageRenderer.class(org/webrtc:VideoRendererGui$YuvImageRenderer.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/VideoRenderer$Callbacks.class(org/webrtc:VideoRenderer$Callbacks.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] /Users/dennis/Desktop/Entwicklung/twyce/app/.meteor/local/cordova-build/platforms/android/src/com/dooble/phonertc/PhoneRTCPlugin.java:420: cannot find symbol
[javac] symbol : method getView()
[javac] location: class org.apache.cordova.CordovaWebView
[javac] ((WebView) webView.getView()).removeView(_videoView);
[javac] ^
[javac] warning: org/webrtc/MediaSource.class(org/webrtc:MediaSource.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/PeerConnection$IceServer.class(org/webrtc:PeerConnection$IceServer.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/MediaConstraints$KeyValuePair.class(org/webrtc:MediaConstraints$KeyValuePair.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: org/webrtc/SessionDescription$Type.class(org/webrtc:SessionDescription$Type.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] Note: Some input files use or override a deprecated API.
[javac] Note: Recompile with -Xlint:deprecation for details.
[javac] Note: Some input files use unchecked or unsafe operations.
[javac] Note: Recompile with -Xlint:unchecked for details.
[javac] 3 errors
[javac] 27 warnings
BUILD FAILED

Is that an Cordova version issue (because Meteor useses 3.x)?

I had the same problem after upgrading a project from 1.1 to 1.2
I had gone through and upgrade all the cordova plugin versions to the current versions on npm ( searching for them on npmjs.com ).
Reverting to my cordoba-plugins file from 1.1 built it fine.