馴龍窩

Open a terminal in ubuntu(ctrl+alt+t) and type this commands:

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sudo add-apt-repository ppa:langdalepl/gvfs-mtp
sudo apt-get update

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Then, launch Software Updater (previously known as Update Manager) and install the available updates. Afther you pdate everything restart pc.

if you want to revert back before making any changes:

sudo ppa-purge ppa:langdalepl/gvfs-mtp

reference web site:

http://android.stackexchange.com/questions/53243/how-do-i-mount-my-samsung-galaxy-s4-on-ubuntu