I upgraded Jira plugin from 2.2.1 to 2.3, and could not make it working (see stack trace below).
other fields are all default.
I tested on a fresh installation: Jenkins 2.44, with only jira plugin 2.3 installed.
I can reproduce the stacktrace by validating my configuration on the configure screen.
RestClientException{statusCode=Optional.absent(), errorCollections=[]}
at com.atlassian.jira.rest.client.internal.async.DelegatingPromise.claim(DelegatingPromise.java:47)
at hudson.plugins.jira.JiraRestService.getMyPermissions(JiraRestService.java:407)
at hudson.plugins.jira.JiraSession.getMyPermissions(JiraSession.java:462)
at hudson.plugins.jira.JiraSite$DescriptorImpl.doValidate(JiraSite.java:763)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at org.kohsuke.stapler.Function$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)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:876)
at org.kohsuke.stapler.MetaClass$6.doDispatch(MetaClass.java:249)
at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:746)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:876)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:649)
at org.kohsuke.stapler.Stapler.service(Stapler.java:238)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:491)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1074)
at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:132)
at hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:123)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1065)
at hudson.security.csrf.CrumbFilter.doFilter(CrumbFilter.java:49)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1065)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:84)
at hudson.security.ChainedServletFilter.doFilter(ChainedServletFilter.java:76)
at hudson.security.HudsonFilter.doFilter(HudsonFilter.java:171)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1065)
at org.kohsuke.stapler.compression.CompressionFilter.doFilter(CompressionFilter.java:49)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1065)
at hudson.util.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:81)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1065)
at org.kohsuke.stapler.DiagnosticThreadNameFilter.doFilter(DiagnosticThreadNameFilter.java:30)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1065)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:365)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:185)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:689)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:391)
at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:146)
at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:139)
at org.mortbay.jetty.Server.handle(Server.java:285)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:457)
at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:765)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:628)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:209)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:357)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:329)
at org.mortbay.thread.BoundedThreadPool$PoolThread.run(BoundedThreadPool.java:475)
Caused by: RestClientException{statusCode=Optional.absent(), errorCollections=[]}
at com.atlassian.jira.rest.client.internal.async.AbstractAsynchronousRestClient$3.apply(AbstractAsynchronousRestClient.java:188)
at com.atlassian.jira.rest.client.internal.async.AbstractAsynchronousRestClient$3.apply(AbstractAsynchronousRestClient.java:182)
at com.atlassian.httpclient.api.ResponsePromiseMapFunction.apply(ResponsePromiseMapFunction.java:62)
at com.atlassian.httpclient.api.ResponsePromiseMapFunction.apply(ResponsePromiseMapFunction.java:12)
at com.atlassian.util.concurrent.Promises$Of$3.apply(Promises.java:285)
at com.atlassian.util.concurrent.Promises$2.onSuccess(Promises.java:162)
at com.google.common.util.concurrent.Futures$6.run(Futures.java:975)
at com.google.common.util.concurrent.MoreExecutors$SameThreadExecutorService.execute(MoreExecutors.java:253)
at com.google.common.util.concurrent.ExecutionList$RunnableExecutorPair.execute(ExecutionList.java:149)
at com.google.common.util.concurrent.ExecutionList.execute(ExecutionList.java:134)
at com.google.common.util.concurrent.AbstractFuture.set(AbstractFuture.java:170)
at com.google.common.util.concurrent.SettableFuture.set(SettableFuture.java:53)
at com.atlassian.util.concurrent.Promises$Of$3.apply(Promises.java:285)
at com.atlassian.util.concurrent.Promises$2.onSuccess(Promises.java:162)
at com.google.common.util.concurrent.Futures$6.run(Futures.java:975)
at com.google.common.util.concurrent.MoreExecutors$SameThreadExecutorService.execute(MoreExecutors.java:253)
at com.google.common.util.concurrent.ExecutionList$RunnableExecutorPair.execute(ExecutionList.java:149)
at com.google.common.util.concurrent.ExecutionList.execute(ExecutionList.java:134)
at com.google.common.util.concurrent.AbstractFuture.set(AbstractFuture.java:170)
at com.google.common.util.concurrent.SettableFuture.set(SettableFuture.java:53)
at com.atlassian.httpclient.apache.httpcomponents.SettableFuturePromiseHttpPromiseAsyncClient$1$1.run(SettableFuturePromiseHttpPromiseAsyncClient.java:46)
at com.atlassian.httpclient.apache.httpcomponents.SettableFuturePromiseHttpPromiseAsyncClient$ThreadLocalDelegateRunnable$1.run(SettableFuturePromiseHttpPromiseAsyncClient.java:197)
at com.atlassian.httpclient.apache.httpcomponents.SettableFuturePromiseHttpPromiseAsyncClient.runInContext(SettableFuturePromiseHttpPromiseAsyncClient.java:90)
at com.atlassian.httpclient.apache.httpcomponents.SettableFuturePromiseHttpPromiseAsyncClient$ThreadLocalDelegateRunnable.run(SettableFuturePromiseHttpPromiseAsyncClient.java:192)
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: org.codehaus.jettison.json.JSONException: A JSONObject text must begin with '{' at character 19 of
<html>
<head>
<title>Wrong host!</title>
</head>
<body>
Please use a valid host.
</body>
</html>
at org.codehaus.jettison.json.JSONTokener.syntaxError(JSONTokener.java:439)
at org.codehaus.jettison.json.JSONObject.<init>(JSONObject.java:169)
at org.codehaus.jettison.json.JSONObject.<init>(JSONObject.java:266)
at com.atlassian.jira.rest.client.internal.async.AbstractAsynchronousRestClient$1.handle(AbstractAsynchronousRestClient.java:145)
at com.atlassian.jira.rest.client.internal.async.AbstractAsynchronousRestClient$3.apply(AbstractAsynchronousRestClient.java:186)
... 26 more