Form the oxd-python tutorial (https://gluu.org/docs/oxd/4.0/tutorials/python/), I have found error while creating and registering site. The error message can be shown as follows: {"error":"no_client_id_returned","error_description":"`client_id` is not returned from OP host. Please check OP log file for error (oxauth.log).","details":null,"reason":null} Then I try to see oxauth.log file on OP server, so I have found some error message as follows: ERROR [qtp817348612-17] [gluu.oxauth.register.ws.rs.RegisterRestWebServiceImpl] (RegisterRestWebServiceImpl.java:319) - HTTP 400 Bad Request javax.ws.rs.WebApplicationException: HTTP 400 Bad Request at org.gluu.oxauth.model.error.ErrorResponseFactory.createWebApplicationException(ErrorResponseFactory.java:102) ~[classes/:?] at org.gluu.oxauth.model.error.ErrorResponseFactory$Proxy$_$$_WeldClientProxy.createWebApplicationException(Unknown Source) ~[classes/:?] at org.gluu.oxauth.register.ws.rs.RegisterRestWebServiceImpl.registerClientImpl(RegisterRestWebServiceImpl.java:225) ~[classes/:?] at org.gluu.oxauth.register.ws.rs.RegisterRestWebServiceImpl.requestRegister(RegisterRestWebServiceImpl.java:135) ~[classes/:?] at org.gluu.oxauth.register.ws.rs.RegisterRestWebServiceImpl$Proxy$_$$_WeldClientProxy.requestRegister(Unknown Source) ~[classes/:?] at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?] at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:?] at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?] at java.lang.reflect.Method.invoke(Method.java:566) ~[?:?] at org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:138) ~[resteasy-jaxrs-3.13.0.Final.jar:3.13.0.Final] at org.jboss.resteasy.core.ResourceMethodInvoker.internalInvokeOnTarget(ResourceMethodInvoker.java:543) ~[resteasy-jaxrs-3.13.0.Final.jar:3.13.0.Final] at org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTargetAfterFilter(ResourceMethodInvoker.java:432) ~[resteasy-jaxrs-3.13.0.Final.jar:3.13.0.Final] at org.jboss.resteasy.core.ResourceMethodInvoker.lambda$invokeOnTarget$0(ResourceMethodInvoker.java:393) ~[resteasy-jaxrs-3.13.0.Final.jar:3.13.0.Final] at org.jboss.resteasy.core.interception.PreMatchContainerRequestContext.filter(PreMatchContainerRequestContext.java:358) ~[resteasy-jaxrs-3.13.0.Final.jar:3.13.0.Final] at org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTarget(ResourceMethodInvoker.java:395) ~[resteasy-jaxrs-3.13.0.Final.jar:3.13.0.Final] at org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:364) ~[resteasy-jaxrs-3.13.0.Final.jar:3.13.0.Final] at org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:337) ~[resteasy-jaxrs-3.13.0.Final.jar:3.13.0.Final] at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:440) ~[resteasy-jaxrs-3.13.0.Final.jar:3.13.0.Final] at org.jboss.resteasy.core.SynchronousDispatcher.lambda$invoke$4(SynchronousDispatcher.java:229) ~[resteasy-jaxrs-3.13.0.Final.jar:3.13.0.Final] at org.jboss.resteasy.core.SynchronousDispatcher.lambda$preprocess$0(SynchronousDispatcher.java:135) ~[resteasy-jaxrs-3.13.0.Final.jar:3.13.0.Final] at org.jboss.resteasy.core.interception.PreMatchContainerRequestContext.filter(PreMatchContainerRequestContext.java:358) ~[resteasy-jaxrs-3.13.0.Final.jar:3.13.0.Final] at org.jboss.resteasy.core.SynchronousDispatcher.preprocess(SynchronousDispatcher.java:138) ~[resteasy-jaxrs-3.13.0.Final.jar:3.13.0.Final] at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:215) ~[resteasy-jaxrs-3.13.0.Final.jar:3.13.0.Final] at org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.service(ServletContainerDispatcher.java:245) ~[resteasy-jaxrs-3.13.0.Final.jar:3.13.0.Final] at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:61) ~[resteasy-jaxrs-3.13.0.Final.jar:3.13.0.Final] at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:56) ~[resteasy-jaxrs-3.13.0.Final.jar:3.13.0.Final] at javax.servlet.http.HttpServlet.service(HttpServlet.java:790) ~[servlet-api-3.1.jar:3.1.0] at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:763) ~[jetty-servlet-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1651) ~[jetty-servlet-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.websocket.server.WebSocketUpgradeFilter.doFilter(WebSocketUpgradeFilter.java:226) ~[websocket-server-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1638) ~[jetty-servlet-9.4.31.v20200723.jar:9.4.31.v20200723] at org.gluu.server.filters.AbstractCorsFilter.handleNonCORS(AbstractCorsFilter.java:362) ~[oxcore-server-4.2.2.Final.jar:?] at org.gluu.server.filters.AbstractCorsFilter.doFilter(AbstractCorsFilter.java:139) ~[oxcore-server-4.2.2.Final.jar:?] at org.gluu.oxauth.filter.CorsFilter.doFilter(CorsFilter.java:118) ~[classes/:?] at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1638) ~[jetty-servlet-9.4.31.v20200723.jar:9.4.31.v20200723] at org.gluu.oxauth.audit.debug.ServletLoggingFilter.doFilter(ServletLoggingFilter.java:67) ~[classes/:?] at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1630) ~[jetty-servlet-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:567) ~[jetty-servlet-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143) ~[jetty-server-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:602) ~[jetty-security-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127) ~[jetty-server-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:235) ~[jetty-server-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1610) ~[jetty-server-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233) ~[jetty-server-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1377) ~[jetty-server-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:188) ~[jetty-server-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:507) ~[jetty-servlet-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1580) ~[jetty-server-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:186) ~[jetty-server-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1292) ~[jetty-server-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141) ~[jetty-server-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:234) ~[jetty-server-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:146) ~[jetty-server-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127) ~[jetty-server-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.server.Server.handle(Server.java:501) ~[jetty-server-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.server.HttpChannel.lambda$handle$1(HttpChannel.java:383) ~[jetty-server-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:556) [jetty-server-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:375) [jetty-server-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:273) [jetty-server-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311) [jetty-io-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:105) [jetty-io-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.io.ChannelEndPoint$1.run(ChannelEndPoint.java:104) [jetty-io-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:336) [jetty-util-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:313) [jetty-util-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:171) [jetty-util-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:129) [jetty-util-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:375) [jetty-util-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:806) [jetty-util-9.4.31.v20200723.jar:9.4.31.v20200723] at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:938) [jetty-util-9.4.31.v20200723.jar:9.4.31.v20200723] at java.lang.Thread.run(Thread.java:834) [?:?] Could someone please help to solve this problem? Thank you so much.