I recommend you to try with the flashall method. You can find a description about how to perform this method here: How to Run the Flashall Script.
If that method doesn’t work, you can also try using the Flash Tool Lite which is a tool used to flash the Edison. You can find a user's guide here:
Thanks for the reply. But unfortunately, none of them works.
Flashtool isn' detecting my edison, while flashall throws this error:
No such keg: /usr/local/Cellar/gnu-getopt
./flashall.sh: line 16: greadlink: command not found
usage: dirname path
./flashall.sh: line 127: -o: command not found
Usage: flashall.sh [-h][--help][--recovery]
Update all software and restore board to its initial state.
-h,--help display this help and exit.
-v verbose output
--recovery recover the board to DFU mode using a dedicated tool,
available only on linux and window hosts.
Never mind. I used a windows machine to flash Edison. The problem seems to be with my OSX El Capitan beta.