Hi Jose,
did you follow the advice above (I cannot find it @ouroumov?) and do you have the following packages installed?:
sudo apt-get install libaacs0 libbluray-bdj libbluray1
libdvdcss2 can be downloaded from here if you cannot find it in the Software Boutique:
64 Bit:
https://pkgs.org/debian-sid/multimedia-main-amd64/libdvdcss2_1.4.0-dmo1_amd64.deb.html
32 Bit:
https://pkgs.org/debian-sid/multimedia-main-i386/libdvdcss2_1.4.0-dmo1_i386.deb.html