skl error

C:\Users\user\Desktop>java -jar skl.exe
[SKlauncher] SKlauncher 3.0-beta.4
[SKlauncher] 22.08.2018 15:35:48
[SKlauncher] System.getProperty('os.name') == 'Windows 10'
[SKlauncher] System.getProperty('os.version') == '10.0'
[SKlauncher] System.getProperty('os.arch') == 'amd64'
[SKlauncher] System.getProperty('java.version') == '1.8.0_181'
[SKlauncher] System.getProperty('java.vendor') == 'Oracle Corporation'
[SKlauncher] System.getProperty('sun.arch.data.model') == '64'
[SKlauncher] Checking connection..
[SKlauncher] java.net.SocketException: Address family not supported by protocol family: connect
        at java.net.DualStackPlainSocketImpl.connect0(Native Method)
        at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
        at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
        at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
        at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
        at java.net.PlainSocketImpl.connect(Unknown Source)
        at java.net.SocksSocketImpl.connect(Unknown Source)
        at java.net.Socket.connect(Unknown Source)
        at sun.net.NetworkClient.doConnect(Unknown Source)
        at sun.net.www.http.HttpClient.openServer(Unknown Source)
        at sun.net.www.http.HttpClient.openServer(Unknown Source)
        at sun.net.www.http.HttpClient.<init>(Unknown Source)
        at sun.net.www.http.HttpClient.New(Unknown Source)
        at sun.net.www.http.HttpClient.New(Unknown Source)
        at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(Unknown Source)
        at sun.net.www.protocol.http.HttpURLConnection.plainConnect0(Unknown Source)
        at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source)
        at sun.net.www.protocol.http.HttpURLConnection.connect(Unknown Source)
        at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(Unknown Source)
        at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
        at java.net.HttpURLConnection.getResponseCode(Unknown Source)
        at pl.skmedix.bootstrap.BootstrapUtils.checkNetwork(BootstrapUtils.java:115)
        at pl.skmedix.bootstrap.BootstrapUtils.checkNetwork(BootstrapUtils.java:104)
        at pl.skmedix.bootstrap.BootstrapController.lambda$initialize$7(BootstrapController.java:89)
        at java.lang.Thread.run(Unknown Source)

[SKlauncher] Response code: 0 - offline
[SKlauncher] Currently we're not able to connect to our server.
[SKlauncher] Server is OFFLINE and you don't have local saved data
[SKlauncher] Cannot read data