Can't discover OPC-UA endpoints

Hello,
I'm a beginning user and I have some fault when trying to discover a third party OPC-UA server.
Our ignition version: 7.9.7 (b2018032914)
Our fault information:
java.util.concurrent.ExecutionException: UaException: status=Bad_Timeout, message=request timed out after 5000ms
java.util.concurrent.CompletableFuture.reportGet(Unknown Source)
java.util.concurrent.CompletableFuture.get(Unknown Source)
com.inductiveautomation.xopc2.client.web.GetEndpointsPanel.onGetEndpoints(GetEndpointsPanel.java:177)
com.inductiveautomation.xopc2.client.web.GetEndpointsPanel.access$100(GetEndpointsPanel.java:38)
com.inductiveautomation.xopc2.client.web.GetEndpointsPanel$2.onSubmit(GetEndpointsPanel.java:75)
org.apache.wicket.markup.html.form.Form$9.component(Form.java:1248)
org.apache.wicket.markup.html.form.Form$9.component(Form.java:1242)
org.apache.wicket.util.visit.Visits.visitPostOrderHelper(Visits.java:274)
org.apache.wicket.util.visit.Visits.visitPostOrder(Visits.java:245)
org.apache.wicket.markup.html.form.Form.delegateSubmit(Form.java:1241)
org.apache.wicket.markup.html.form.Form.process(Form.java:923)
org.apache.wicket.markup.html.form.Form.onFormSubmitted(Form.java:769)
org.apache.wicket.markup.html.form.Form.onFormSubmitted(Form.java:702)
sun.reflect.GeneratedMethodAccessor67.invoke(Unknown Source)
sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
java.lang.reflect.Method.invoke(Unknown Source)
org.apache.wicket.RequestListenerInterface.internalInvoke(RequestListenerInterface.java:258)
org.apache.wicket.RequestListenerInterface.invoke(RequestListenerInterface.java:216)
org.apache.wicket.core.request.handler.ListenerInterfaceRequestHandler.invokeListener(ListenerInterfaceRequestHandler.java:240)
org.apache.wicket.core.request.handler.ListenerInterfaceRequestHandler.respond(ListenerInterfaceRequestHandler.java:226)
org.apache.wicket.request.cycle.RequestCycle$HandlerExecutor.respond(RequestCycle.java:814)
org.apache.wicket.request.RequestHandlerStack.execute(RequestHandlerStack.java:64)
org.apache.wicket.request.cycle.RequestCycle.execute(RequestCycle.java:253)
org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:210)
org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:281)
org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:188)
org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:245)
org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1668)
org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:581)
org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548)
org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:226)
org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1160)
org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:511)
org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)
org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1092)
org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
org.eclipse.jetty.server.handler.HandlerList.handle(HandlerList.java:52)
org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:134)
org.eclipse.jetty.server.Server.handle(Server.java:518)
org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:308)
org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:244)
org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:273)
org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:95)
org.eclipse.jetty.io.SelectChannelEndPoint$2.run(SelectChannelEndPoint.java:93)
org.eclipse.jetty.util.thread.strategy.ExecuteProduceConsume.produceAndRun(ExecuteProduceConsume.java:246)
org.eclipse.jetty.util.thread.strategy.ExecuteProduceConsume.run(ExecuteProduceConsume.java:156)
org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:654)
org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:572)
java.lang.Thread.run(Unknown Source)
org.eclipse.milo.opcua.stack.core.UaException: request timed out after 5000ms
org.eclipse.milo.opcua.stack.client.UaTcpStackClient.lambda$scheduleRequestTimeout$13(UaTcpStackClient.java:326)
io.netty.util.HashedWheelTimer$HashedWheelTimeout.expire(HashedWheelTimer.java:581)
io.netty.util.HashedWheelTimer$HashedWheelBucket.expireTimeouts(HashedWheelTimer.java:655)
io.netty.util.HashedWheelTimer$Worker.run(HashedWheelTimer.java:367)
java.lang.Thread.run(Unknown Source)

Thanks so much.

Looks pretty simple:

The target server simply did not respond. At all. This is usually a network routing or firewall issue.

You are extremely likely to also suffer from the elimination of older TLS protocols throughout most networks. You will likely need to upgrade to at least the last v7.9 release, and since that has been end-of-life for a while now, you need to plan for upgrading to v8.1.