In recent versions of Google Chrome and Chromium, the Google Music app will fail to open the mini player and fail to upload music stating that "This computer is not recognized" on many installs of Linux Mint, Ubuntu and possibly other distro's. This is an issue with chromium trying to look for a sym link in the path "/dev/disk/by-uuid/" that links to "/dev/sda1" which sometimes doesn't exist. It needs to be fixed upstream (You can support this bug report here https://code.google.com/p/chromium/issues/detail?id=492174)

At the momment there is a temporary fix that will get it back up and running again.

1. Type sudo ln -s /dev/sda1 /dev/disk/by-uuid/hardcoding_things_is_evil in the terminal

2. Type sudo gedit /etc/rc.local in the terminal

3. And add a line before "exit 0" by typing in ln -s /dev/sda1 /dev/disk/by-uuid/hardcoding_things_is_evil

The First command makes an imaginary link to "/dev/sda1"

Lines 2-3 put the same command in rc.local so it runs at start up and creates that link again so you don't have to manually type it in every time you reboot.

This should get your songs uploading and mini player working again.