I have recently upgraded jenkins on latest version & I'm trying to make changes in the configuration through Manage jenkins > Configure > but it is not getting saved & throwing following message -

A problem occurred while processing the request. Please check our bug tracker to see if a similar problem has already been reported. If it is already reported, please vote and put a comment on it to let us gauge the impact of the problem. If you think this is a new issue, please file a new issue. When you file an issue, make sure to add the entire stack trace, along with the version of Jenkins and relevant plugins. The users list might be also useful in understanding what has happened.

Stack trace

javax.servlet.ServletException: java.lang.IllegalArgumentException: Host name may not be null
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:796)
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:790)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:812)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1669)
at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:135)
at com.smartcodeltd.jenkinsci.plugin.assetbundler.filters.LessCSS.doFilter(LessCSS.java:47)
at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:132)
at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:201)
at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:178)
at net.bull.javamelody.PluginMonitoringFilter.doFilter(PluginMonitoringFilter.java:85)
at org.jvnet.hudson.plugins.monitoring.HudsonMonitoringFilter.doFilter(HudsonMonitoringFilter.java:102)
at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:132)
at hudson.plugins.greenballs.GreenBallFilter.doFilter(GreenBallFilter.java:59)
at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:132)
at hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:126)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1652)
at hudson.security.csrf.CrumbFilter.doFilter(CrumbFilter.java:49)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1652)
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:142)
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:1652)
at org.kohsuke.stapler.compression.CompressionFilter.doFilter(CompressionFilter.java:49)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1652)
at hudson.util.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:82)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1652)
at org.kohsuke.stapler.DiagnosticThreadNameFilter.doFilter(DiagnosticThreadNameFilter.java:30)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1652)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:585)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:553)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:223)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1127)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:515)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1061)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
at org.eclipse.jetty.server.Server.handle(Server.java:499)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:311)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:257)
at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:544)
at winstone.BoundedExecutorService$1.run(BoundedExecutorService.java:77)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.IllegalArgumentException: Host name may not be null
at org.apache.http.HttpHost.<init>(HttpHost.java:79)
at org.apache.http.impl.client.cache.CachingHttpAsyncClient.execute(CachingHttpAsyncClient.java:276)
at com.atlassian.httpclient.apache.httpcomponents.SettableFuturePromiseHttpPromiseAsyncClient.execute(SettableFuturePromiseHttpPromiseAsyncClient.java:36)
at com.atlassian.httpclient.apache.httpcomponents.DefaultHttpClient.doExecute(DefaultHttpClient.java:247)
at com.atlassian.httpclient.apache.httpcomponents.DefaultHttpClient.execute(DefaultHttpClient.java:181)
at com.atlassian.httpclient.apache.httpcomponents.DefaultRequest.get(DefaultRequest.java:47)
at com.atlassian.jira.rest.client.internal.async.AbstractAsynchronousRestClient.getAndParse(AbstractAsynchronousRestClient.java:67)
at org.jenkinsci.plugins.JiraTestResultReporter.restclientextensions.JiraRestClientExtension.getStatuses(JiraRestClientExtension.java:42)
at org.jenkinsci.plugins.JiraTestResultReporter.JiraTestDataPublisher$JiraTestDataPublisherDescriptor.tryCreatingStatusToCategoryMap(JiraTestDataPublisher.java:373)
at org.jenkinsci.plugins.JiraTestResultReporter.JiraTestDataPublisher$JiraTestDataPublisherDescriptor.configure(JiraTestDataPublisher.java:363)
at jenkins.model.Jenkins.configureDescriptor(Jenkins.java:3422)
at jenkins.model.Jenkins.doConfigSubmit(Jenkins.java:3385)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.kohsuke.stapler.Function$InstanceFunction.invoke(Function.java:324)
at org.kohsuke.stapler.Function.bindAndInvoke(Function.java:167)
at org.kohsuke.stapler.Function.bindAndInvokeAndServeResponse(Function.java:100)
at org.kohsuke.stapler.MetaClass$1.doDispatch(MetaClass.java:124)
at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:58)
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:746)
... 63 more