USB KEY DOESN'T WORKS : ubuntu 14.04 LTS - Trusty version

Good day,

I using ubuntu 14.04 LTS - Trusty version and my usb key doesn't works when it mounted.

Please find the Message got : unable to execute the specified command. The file or folder file: // media / dennis / EOF6-31C3 does not exist

Thanks so much to help me for finding the solution with this current problem. Dennis : dgf@mailoo.org