Hi Franck.
Mint 17.2 is based on an older version of ububtu (14.04 I think).
I had the same problem with my xe2 raf files, I had to upgrade to an ubuntu 16.04 distro which solved the problem.
There was a discussion on this site Problems with RAW Files by Fuji x E2 / Firmware 4.0 - #7 by Claes which had a work around (but I couldn’t get it to work)
Hope that helps 
Keith.