Stack java.net.UnknownHostException: C when starting Karaf 4.x on Windows

2017-09-05 08:03:26,878 | ERROR | onfig-2-thread-1 | ServerControllerImpl             | 217 - org.ops4j.pax.web.pax-web-undertow - 6.0.6 | Exception while starting Undertow
java.net.UnknownHostException: C
        at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:184) ~[?:?]
        at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172) ~[?:?]
        at java.net.Socket.connect(Socket.java:589) ~[?:?]
        at java.net.Socket.connect(Socket.java:538) ~[?:?]
        at sun.net.ftp.impl.FtpClient.doConnect(FtpClient.java:957) ~[?:?]
        at sun.net.ftp.impl.FtpClient.tryConnect(FtpClient.java:917) ~[?:?]
        at sun.net.ftp.impl.FtpClient.connect(FtpClient.java:1012) ~[?:?]
        at sun.net.ftp.impl.FtpClient.connect(FtpClient.java:998) ~[?:?]
        at sun.net.www.protocol.ftp.FtpURLConnection.connect(FtpURLConnection.java:294) ~[?:?]
        at sun.net.www.protocol.ftp.FtpURLConnection.getInputStream(FtpURLConnection.java:393) ~[?:?]
        at java.net.URL.openStream(URL.java:1045) ~[?:?]
        at org.ops4j.pax.web.service.undertow.internal.ServerControllerImpl.doStart(ServerControllerImpl.java:219) ~[?:?]
        at org.ops4j.pax.web.service.undertow.internal.ServerControllerImpl.start(ServerControllerImpl.java:118) ~[?:?]
        at org.ops4j.pax.web.service.internal.Activator.updateController(Activator.java:375) ~[?:?]
        at org.ops4j.pax.web.service.internal.Activator.lambda$scheduleUpdateFactory$2(Activator.java:291) ~[?:?]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:?]
        at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:?]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:?]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:?]
        at java.lang.Thread.run(Thread.java:745) [?:?]
2017-09-05 08:03:26,882 | ERROR | onfig-2-thread-1 | Activator                        | 215 - org.ops4j.pax.web.pax-web-runtime - 6.0.6 | Unable to start pax web server: Exception while starting Undertow
java.lang.RuntimeException: Exception while starting Undertow
        at org.ops4j.pax.web.service.undertow.internal.ServerControllerImpl.doStart(ServerControllerImpl.java:238) ~[?:?]
        at org.ops4j.pax.web.service.undertow.internal.ServerControllerImpl.start(ServerControllerImpl.java:118) ~[?:?]
        at org.ops4j.pax.web.service.internal.Activator.updateController(Activator.java:375) ~[?:?]
        at org.ops4j.pax.web.service.internal.Activator.lambda$scheduleUpdateFactory$2(Activator.java:291) ~[?:?]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:?]
        at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:?]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:?]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:?]
        at java.lang.Thread.run(Thread.java:745) [?:?]
Caused by: java.net.UnknownHostException: C
        at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:184) ~[?:?]
        at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172) ~[?:?]
        at java.net.Socket.connect(Socket.java:589) ~[?:?]
        at java.net.Socket.connect(Socket.java:538) ~[?:?]
        at sun.net.ftp.impl.FtpClient.doConnect(FtpClient.java:957) ~[?:?]
        at sun.net.ftp.impl.FtpClient.tryConnect(FtpClient.java:917) ~[?:?]
        at sun.net.ftp.impl.FtpClient.connect(FtpClient.java:1012) ~[?:?]
        at sun.net.ftp.impl.FtpClient.connect(FtpClient.java:998) ~[?:?]
        at sun.net.www.protocol.ftp.FtpURLConnection.connect(FtpURLConnection.java:294) ~[?:?]
        at sun.net.www.protocol.ftp.FtpURLConnection.getInputStream(FtpURLConnection.java:393) ~[?:?]
        at java.net.URL.openStream(URL.java:1045) ~[?:?]
        at org.ops4j.pax.web.service.undertow.internal.ServerControllerImpl.doStart(ServerControllerImpl.java:219) ~[?:?]
        ... 8 more