Caused by: java.lang.IllegalArgumentException: Could not open sound file: BossMusic.mp3
at greenfoot.sound.SoundExceptionHandler.handleIOException(SoundExceptionHandler.java:66)
at greenfoot.sound.SoundFactory.createSound(SoundFactory.java:120)
at greenfoot.GreenfootSound.<init>(GreenfootSound.java:54)
at Musik.<clinit>(Musik.java:13)
... 11 more
Caused by: java.io.FileNotFoundException: Could not find file: BossMusic.mp3
at greenfoot.util.GreenfootUtil.getURL(GreenfootUtil.java:189)
at greenfoot.sound.SoundFactory.createSound(SoundFactory.java:99)
... 13 more