Hi, Guys:

I'm trying to create a VCS with Github , but hit connect time out issue, attach my settings as below

When I click "Sign in to Github" button, I got below error :

Unexpected Error

This was not supposed to happen. Please provide the error details to your TeamCity server maintainer.
If you maintain this TeamCity installation and the request seems legit please report this error to JetBrains.

Trace: org.apache.http.conn.ConnectTimeoutException: Connect to github.com:443 [github.com/13.250.177.223] failed: connect timed out
	at org.apache.http.impl.conn.HttpClientConnectionOperator.connect(HttpClientConnectionOperator.java:134)
	at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.connect(PoolingHttpClientConnectionManager.java:319)
	at org.apache.http.impl.execchain.MainClientExec.establishRoute(MainClientExec.java:363)
	at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:219)
	at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:195)
	at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:86)
	at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:108)
	at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:184)
	at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82)
	at jetbrains.buildServer.util.HTTPRequestBuilder$ApacheClient43RequestHandler.doRequest(HTTPRequestBuilder.java:115)
	at jetbrains.buildServer.serverSide.oauth.github.GitHubAccessTokenController.doHandle(GitHubAccessTokenController.java:154)
	at jetbrains.buildServer.controllers.BaseController.handleRequestInternal(BaseController.java:114)
	at org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:174)
	at jetbrains.buildServer.controllers.BaseController.handleRequest(BaseController.java:93)
	at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:50)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
	at jetbrains.buildServer.maintenance.TeamCityDispatcherServlet.processedByMainServlet(TeamCityDispatcherServlet.java:34)
	at jetbrains.buildServer.maintenance.TeamCityDispatcherServlet.service(TeamCityDispatcherServlet.java:15)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at jetbrains.buildServer.web.jsp.JspPrecompilerFilter.doFilter(JspPrecompilerFilter.java:92)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at jetbrains.buildServer.web.DisableSessionIdFromUrlFilter.doFilter(DisableSessionIdFromUrlFilter.java:6)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at jetbrains.buildServer.web.UserIdProviderFilter.doFilter(UserIdProviderFilter.java:8)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at jetbrains.buildServer.web.NodeInfoHeaderFilter.doFilter(NodeInfoHeaderFilter.java:8)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.springframework.web.filter.CompositeFilter$VirtualFilterChain.doFilter(CompositeFilter.java:107)
	at jetbrains.buildServer.diagnostic.web.DiagnosticFilter.doFilter(DiagnosticFilter.java:60)
	at org.springframework.web.filter.CompositeFilter$VirtualFilterChain.doFilter(CompositeFilter.java:112)
	at jetbrains.buildServer.web.DependencyParametersCalculationContextFilter.doFilter(DependencyParametersCalculationContextFilter.java:3)
	at org.springframework.web.filter.CompositeFilter$VirtualFilterChain.doFilter(CompositeFilter.java:112)
	at jetbrains.buildServer.web.HttpSecurityHeadersFilter.doFilter(HttpSecurityHeadersFilter.java:58)
	at org.springframework.web.filter.CompositeFilter$VirtualFilterChain.doFilter(CompositeFilter.java:112)
	at jetbrains.buildServer.web.CSRFFilter.doFilter(CSRFFilter.java:112)
	at org.springframework.web.filter.CompositeFilter$VirtualFilterChain.doFilter(CompositeFilter.java:112)
	at org.springframework.web.filter.CompositeFilter.doFilter(CompositeFilter.java:73)
	at jetbrains.buildServer.web.DelegatingFilter.doFilter(DelegatingFilter.java:61)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at jetbrains.buildServer.web.ResponseFragmentFilter.doFilter(ResponseFragmentFilter.java:12)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:493)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:798)
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:808)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1498)
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:748)
Caused by: java.net.SocketTimeoutException: connect timed out
	at java.net.PlainSocketImpl.socketConnect(Native Method)
	at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
	at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
	at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
	at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
	at java.net.Socket.connect(Socket.java:607)
	at org.apache.http.conn.ssl.SSLConnectionSocketFactory.connectSocket(SSLConnectionSocketFactory.java:244)
	at jetbrains.buildServer.util.http.SSLConnectionSocketFactoryWithSNI.connectSocket(SSLConnectionSocketFactoryWithSNI.java:1)
	at org.apache.http.impl.conn.HttpClientConnectionOperator.connect(HttpClientConnectionOperator.java:125)
	... 72 more

actually, I can access https://github.com/taowan1/version_control_project

If I click "Test connection" button, it's also time out 

below log is from teamcity-vcs.log 

Caused by: org.eclipse.jgit.errors.TransportException: taowan1@github.com:taowan1/version_control_project.git: timeout: socket is not established
at org.eclipse.jgit.transport.JschConfigSessionFactory.getSession(JschConfigSessionFactory.java:159)
at org.eclipse.jgit.transport.SshTransport.getSession(SshTransport.java:137)
at org.eclipse.jgit.transport.TransportGitSsh$SshFetchConnection.<init>(TransportGitSsh.java:262)
at org.eclipse.jgit.transport.TransportGitSsh.openFetch(TransportGitSsh.java:161)
at jetbrains.buildServer.buildTriggers.vcs.git.GitVcsSupport.getRemoteRefs(GitVcsSupport.java:506)
at jetbrains.buildServer.buildTriggers.vcs.git.GitVcsSupport.getRemoteRefs(GitVcsSupport.java:483)
... 77 more
Caused by: com.jcraft.jsch.JSchException: timeout: socket is not established
at com.jcraft.jsch.Util.createSocket(Util.java:394)
at com.jcraft.jsch.Session.connect(Session.java:215)
at org.eclipse.jgit.transport.JschConfigSessionFactory.getSession(JschConfigSessionFactory.java:116)