Doesn't work when I turn on wi-fi

I tried to install manager on a mac book air 10.9.5
It doesn’t work when it is connected to Internet. The screen shows me something strange…
The weirdest thing is that with my mc book pro, connected to the same wi-fi, it works correctly.
Any suggestions?

Proxy Enabled? Check the Network settings under the System Preferences (and check if they are the same, except the IP-address of-course).