Suddently ask domain and pw to access local network

[GR9000]

Bought a new router and plug a USB drive on it.

Can't access their content because de VLC App (on my Fire Stick) constantlty ask the 'Domain name' and password.
However, the local network isn't passwork protected. I can access it trough the Kodi App (without any password), but I prefer the VLC app.

More precisely it says :

" The computer you are trying to connect to requires authentication. PLease provide a username (ideally a domain name using the format DOMAIN; username and a password"

I have tried everything... domain name and password to access local network, even if its no lock. Nothing works.
Anyways...its not even suppose to ask me that. What's wrong?

Please help!

ps.: I don't know how to upload a picture here