Fix start with only screen.

src/main/webapp/js/webrtc_adaptor.js

@@ -237,7 +237,6 @@ export class WebRTCAdaptor
 					else{
 						this.updateAudioTrack(audioStream,streamId,null);
 					}
-					this.checkWebSocketConnection();
 				}
 				else if(this.publishMode == "screen+camera" ){
 					if(audioTrack.length > 0 ){
@@ -256,6 +255,7 @@ export class WebRTCAdaptor
 					}
 					this.gotStream(stream);
 				}
+				this.checkWebSocketConnection();
 			}, true)
 		}
 		else {
@@ -792,23 +792,28 @@ export class WebRTCAdaptor
 	 */
 	updateLocalAudioStream(stream, onEndedCallback) 
 	{
-		var audioTrack = this.localStream.getAudioTracks()[0];
 		var newAudioTrack = stream.getAudioTracks()[0];
 
-		if (audioTrack != null) 
+		if (this.localStream != null && this.localStream.getAudioTracks()[0] != null) 
 		{
+			var audioTrack = this.localStream.getAudioTracks()[0];
 			this.localStream.removeTrack(audioTrack);
 			audioTrack.stop();
+			this.localStream.addTrack(newAudioTrack);
+		}
+		else if(this.localStream != null){
+			this.localStream.addTrack(newAudioTrack);
+		}
+		else{
+			this.localStream = stream;
 		}
-
-
-		this.localStream.addTrack(newAudioTrack);
-
 
+
 		if (this.localVideo != null) 
 		{   //it can be null
 			this.localVideo.srcObject = this.localStream;
 		}
+
 		if (onEndedCallback != null) {
 			stream.getAudioTracks()[0].onended = function(event) {
 				onEndedCallback(event);
@@ -826,11 +831,16 @@ export class WebRTCAdaptor
 			this.desktopStream.getVideoTracks()[0].stop();
 		}
 
-		if(this.localStream != null){
+		var newVideoTrack = stream.getVideoTracks()[0];
+
+		if(this.localStream != null && this.localStream.getVideoTracks()[0] != null){
 			var videoTrack = this.localStream.getVideoTracks()[0];
 			this.localStream.removeTrack(videoTrack);
 			videoTrack.stop();
-			this.localStream.addTrack(stream.getVideoTracks()[0]);
+			this.localStream.addTrack(newVideoTrack);
+		}
+		else if(this.localStream != null){
+			this.localStream.addTrack(newVideoTrack);
 		}
 		else{
 			this.localStream = stream;