If changed my primary browser from Chrome to Firefox, because Chrome heated my computer very hard.

When I wanted to listen to music on music.google.com, it didn't worked. I checked my chache and my cookeis, because I've read this in a guide, but this did not work. Now, I know how it works:

Probably, your have enabled HTML5 Audio. You need to turn it off, to use Flash instead.

1. Go to music.google.com 

2. Click on the settings-wheel (picture).

3. Click on Labs.

4.On HTML5 Audio, click Enabled and then Save changes (picture).

That's it! Enjoy your music again!