Can't install on Kobo Aura n514

[slyholborn]

Hello, i've got 2 Aura n514 and i can't install Koreader on any of it. I tried auto and manual method : all seems to work fine on my terminal.

  inflating: /run/media/sylvain/KOBOeReader/.adds/koreader/libs/libjpeg.so.8  
  inflating: /run/media/sylvain/KOBOeReader/.adds/koreader/libs/libdjvulibre.so.21  
* Sanity check . . .
* More sanity checks . . .
* Flush to storage device . . .
* Installation successful!
* Please make sure to eject & unplug your device safely!

The reader reboots, i have new books, new directories, but no icon to launch koreader.
Is it because i use them without accounts? To start them, i had to run

INSERT INTO user(UserID,UserKey) VALUES('1','');

with mysql3

Any ideas? Thanks !