javax.servlet.ServletException: java.lang.NullPointerException
    at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:796)
    at org.kohsuke.stapler.Stapler.invoke(Stapler.java:876)
    at org.kohsuke.stapler.MetaClass$4.doDispatch(MetaClass.java:211)
    at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
    at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:746)
    at org.kohsuke.stapler.Stapler.invoke(Stapler.java:876)
    at org.kohsuke.stapler.Stapler.invoke(Stapler.java:649)
    at org.kohsuke.stapler.Stapler.service(Stapler.java:238)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:848)
    at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:686)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1494)
    at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:123)
    at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:198)
    at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:176)
    at net.bull.javamelody.PluginMonitoringFilter.doFilter(PluginMonitoringFilter.java:85)
    at org.jvnet.hudson.plugins.monitoring.HudsonMonitoringFilter.doFilter(HudsonMonitoringFilter.java:99)
    at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:120)
    at hudson.plugins.greenballs.GreenBallFilter.doFilter(GreenBallFilter.java:58)
    at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:120)
    at hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:114)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1482)
    at hudson.security.csrf.CrumbFilter.doFilter(CrumbFilter.java:48)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1482)
    at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:84)
    at hudson.security.UnwrapSecurityExceptionFilter.doFilter(UnwrapSecurityExceptionFilter.java:51)
    at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
    at jenkins.security.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:117)
    at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
    at org.acegisecurity.providers.anonymous.AnonymousProcessingFilter.doFilter(AnonymousProcessingFilter.java:125)
    at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
    at org.acegisecurity.ui.rememberme.RememberMeProcessingFilter.doFilter(RememberMeProcessingFilter.java:135)
    at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
    at org.acegisecurity.ui.AbstractProcessingFilter.doFilter(AbstractProcessingFilter.java:271)
    at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
    at jenkins.security.BasicHeaderProcessor.doFilter(BasicHeaderProcessor.java:93)
    at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
    at org.acegisecurity.context.HttpSessionContextIntegrationFilter.doFilter(HttpSessionContextIntegrationFilter.java:249)
    at hudson.security.HttpSessionContextIntegrationFilter2.doFilter(HttpSessionContextIntegrationFilter2.java:67)
    at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
    at hudson.security.ChainedServletFilter.doFilter(ChainedServletFilter.java:76)
    at hudson.security.HudsonFilter.doFilter(HudsonFilter.java:171)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1482)
    at org.kohsuke.stapler.compression.CompressionFilter.doFilter(CompressionFilter.java:49)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1482)
    at hudson.util.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:81)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1482)
    at org.kohsuke.stapler.DiagnosticThreadNameFilter.doFilter(DiagnosticThreadNameFilter.java:30)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1474)
    at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:499)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:137)
    at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:533)
    at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:231)
    at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1086)
    at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:428)
    at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:193)
    at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1020)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:135)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:116)
    at org.eclipse.jetty.server.Server.handle(Server.java:370)
    at org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:489)
    at org.eclipse.jetty.server.AbstractHttpConnection.headerComplete(AbstractHttpConnection.java:949)
    at org.eclipse.jetty.server.AbstractHttpConnection$RequestHandler.headerComplete(AbstractHttpConnection.java:1011)
    at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:644)
    at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:235)
    at org.eclipse.jetty.server.AsyncHttpConnection.handle(AsyncHttpConnection.java:82)
    at org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle(SelectChannelEndPoint.java:668)
    at org.eclipse.jetty.io.nio.SelectChannelEndPoint$1.run(SelectChannelEndPoint.java:52)
    at winstone.BoundedExecutorService$1.run(BoundedExecutorService.java:77)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NullPointerException
    at org.kohsuke.github.Requester.handleApiError(Requester.java:486)
    at org.kohsuke.github.Requester._to(Requester.java:245)
    at org.kohsuke.github.Requester.to(Requester.java:191)
    at org.kohsuke.github.GitHub.getMyself(GitHub.java:261)
    at org.kohsuke.github.GitHub.<init>(GitHub.java:137)
    at org.kohsuke.github.GitHubBuilder.build(GitHubBuilder.java:195)
    at org.kohsuke.github.GitHub.connectUsingOAuth(GitHub.java:187)
    at org.jenkinsci.plugins.GithubAuthenticationToken.<init>(GithubAuthenticationToken.java:87)
    at org.jenkinsci.plugins.GithubSecurityRealm.doFinishLogin(GithubSecurityRealm.java:386)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.kohsuke.stapler.Function$InstanceFunction.invoke(Function.java:298)
    at org.kohsuke.stapler.Function.bindAndInvoke(Function.java:161)
    at org.kohsuke.stapler.Function.bindAndInvokeAndServeResponse(Function.java:96)
    at org.kohsuke.stapler.MetaClass$1.doDispatch(MetaClass.java:121)
    at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
    at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:746)
    ... 70 more