am new to Jenkins. I have installed Jenkins on Windows server, which is behind a Firewall. Server is started and able to login to Jenkins URL. I am trying to install VSS plugin.

I have followed below steps to install VSS plugin. But I still don't see any plugins under "Installed" tab

1. I have downloaded VSS plugin from Github as zip file and renamed it to hpi file.
2. I have copied file to $JENKINS_HOME/plugins directory.
3. Restarted Jenkins Windows service
4. I could see hpi file exploded and could see the content

Not sure whether below error relevant to that, but I could see below error in the file "Download metadata".

Kindly help me to resolve the issue. Many thanks in advance

Started at Wed Oct 05 16:45:30 CDT 2016
FATAL: no protocol: ?id=default&version=2.11
[8mha:AAAAWB+LCAAAAAAAAP9b85aBtbiIQSmjNKU4P08vOT+vOD8nVc8DzHWtSE4tKMnMz/PLL0ldFVf2c+b/lb5MDAwVRQxSaBqcITRIIQMEMIIUFgAAckCEiWAAAAA= [0mjava.net.MalformedURLException: no protocol: ?id=default&version=2.11
at java.net.URL.<init>(Unknown Source)
at java.net.URL.<init>(Unknown Source)
at java.net.URL.<init>(Unknown Source)
at hudson.model.UpdateSite.updateDirectlyNow(UpdateSite.java:176)
at hudson.PluginManager.doCheckUpdatesServer(PluginManager.java:1508)
at jenkins.model.DownloadSettings$DailyCheck.execute(DownloadSettings.java:138)
at hudson.model.AsyncPeriodicWork$1.run(AsyncPeriodicWork.java:100)
at java.lang.Thread.run(Unknown Source)
Finished at Wed Oct 05 16:45:30 CDT 2016. 50ms