Errors from zekr log

16:14:15 [ERROR] (AudioPlayerUiController:123) - Error occured in play-pause method.
net.sf.zekr.engine.audio.PlayerException: javazoom.jlgui.basicplayer.BasicPlayerException: Cannot init line
    at net.sf.zekr.engine.audio.DefaultPlayerController.play(DefaultPlayerController.java:162)
    at net.sf.zekr.ui.AudioPlayerUiController.playerTogglePlayPause(AudioPlayerUiController.java:211)
    at net.sf.zekr.engine.audio.ui.AudioPlayerForm$8.widgetSelected(AudioPlayerForm.java:438)
    at org.eclipse.swt.widgets.TypedListener.handleEvent(Unknown Source)
    at org.eclipse.swt.widgets.EventTable.sendEvent(Unknown Source)
    at org.eclipse.swt.widgets.Widget.sendEvent(Unknown Source)
    at org.eclipse.swt.widgets.Display.runDeferredEvents(Unknown Source)
    at org.eclipse.swt.widgets.Display.readAndDispatch(Unknown Source)
    at net.sf.zekr.ui.BaseForm.loopEver(BaseForm.java:34)
    at net.sf.zekr.ZekrMain.startZekr(ZekrMain.java:63)
    at net.sf.zekr.ZekrMain.main(ZekrMain.java:91)
Caused by: javazoom.jlgui.basicplayer.BasicPlayerException: Cannot init line
    at javazoom.jlgui.basicplayer.BasicPlayer.startPlayback(Unknown Source)
    at javazoom.jlgui.basicplayer.BasicPlayer.play(Unknown Source)
    at net.sf.zekr.engine.audio.DefaultPlayerController.play(DefaultPlayerController.java:159)
    ... 10 more
Caused by: javax.sound.sampled.LineUnavailableException: Audio Device Unavailable
    at com.sun.media.sound.HeadspaceMixer.nResume(Native Method)
    at com.sun.media.sound.HeadspaceMixer.implOpen(HeadspaceMixer.java:346)
    at com.sun.media.sound.AbstractMixer.open(AbstractMixer.java:286)
    at com.sun.media.sound.AbstractMixer.open(AbstractMixer.java:323)
    at com.sun.media.sound.AbstractDataLine.open(AbstractDataLine.java:103)
    at com.sun.media.sound.MixerSourceLine.open(MixerSourceLine.java:39)
    at javazoom.jlgui.basicplayer.BasicPlayer.openLine(Unknown Source)
    at javazoom.jlgui.basicplayer.BasicPlayer.initLine(Unknown Source)
    ... 13 more
16:14:15 [DEBUG] (AudioPlayerUiController:107) - Player stop status.