A connection to the server could not be established

Hello,

I've installed readynas-remote on my notebook for about half a year now. Everything worked fine. But since yesterday, when I try to connect with readynas remote the following error raises:

A connection to the server could not be established; this error may occur if you are ona network that uses a proxy server or if you have previoulsy configured Leaf to use a proxy server and the proxy server has changed.
Would you like to configure ReadyNas Remote to use a proxy to connect to the Internet?

I tried to reinstall readynasremote on my notebook but the same error raises again. In my network there is also no Proxy or something else, which may occur this problem.

When I try to connect to my nas by another PC and readynas remote everything works fine.

Does anyone know a solution for my problem?

Thanks

I'm using Windows 8.1