arduino yun doesn't start config panel

hello,
my new yun can't start the (pre-configured) web config panel at http://arduino.local or 192.168.240.1. (/cgi-bin/luci/webpanel/homepage)
calling it the result is "bad gateway".
under /www/cgi-bin there is only luci
how to configure?
ty
Flavio

Does it happen even after a couple of minutes?

it happens immediately.
I never get the access to config panel but wifi ssh and load of sketch go right.

And what about waiting a couple of minutes and retry? Still not working?

same.
now it doesn't solve also http://arduino.local but it try to work only using ip address. (192.168.240.1)
I tried to clean cache and I checked if the proxy were off (IE),

Are you using IE? Can you try with Chrome or Firefox?
arduino.local on windows is tricky as it requires bonjour print services installed and your firewall open on port 5353 UDP
"arduino" in "arduino.local" is the name of your board so, if you changed it to myyun, it will be "myyun.local"

firefox adds www. anycase i tried with browser from android. same result

and tried with firefox with IP......same.
I see now that wlan led never blinks orange but i though the connection was always ok because ssh function correctly.