Ok I've some good news...
Since this morning update.
1) Turn on both razer services (Services, Razer Chroma SDK and Game Scanner)
2) Edit the config file (C:\Users\xxxxx\Documents\BnS\NCWEST\ClientConfiguration.xml) put back the chroma setting to "y" (use-chroma-keyboard)
3) Clear that folder (C:\Program Files (x86)\NCSOFT\BnS\bin\GameGuard)
4) Do a file repair, start the game
That finally worked on my pc (my laptop didn't have any problem.