1.InvalidStateError: An attempt was made to use an object that is not, or is no longer,usable at function below

***startRecordingnew()***

var recordButton, stopButton, recorder;


window.onload = function () {

    navigator.mediaDevices.getUserMedia({
        audio: true
    })
    .then(function (stream) {
        if (recorder == null) {
            recorder = new MediaRecorder(stream);
            alert(stream)
            recorder.addEventListener('dataavailable', onRecordingReady);
        }
    }).catch(function (err) {
        alert(err)
    });;
};


function startRecordingnew() {

    recorder.start();

}

function stopRecordingnew() {

    recorder.stop();
}