Prolobe Online Absolute Pitch Ear Training

The APP Starts, but I can't hear any sound when it starts, then it stops and says "Time ran out, saving progress..."
After that it doesn't do anything, it's just frozen (the timer is frozen too).

I don't understand? I'm running Mozilla on Linux (Mint version), the test in the settings tab of the app worked, and everything seems to run fine until I start the training?

Help please?