Error 500 when executing a query / wd / hub / sessions to docker-selenium

We start the Selenium server ( elgalu / docker-selenium ):

require('child_process').execSync( `docker run -d --name="selenium-tester-3" ` + `-p 40002:24444 -p 40012:25900 --shm-size=1g ` + `-e NOVNC=false -e SCREEN_WIDTH=1920 -e SCREEN_HEIGHT=1480 -e VNC_PASSWORD=hola ` + `elgalu/selenium` ); 

Connect to it via chimpy :

 [chimp][session-manager] checking connection to selenium server [11:40:53] COMMAND GET "/wd/hub/status" [11:40:53] DATA {} [11:40:53] RESULT { "ready":true,"message":"Hub has capacity", "build":{"revision":"e82be7d358","time":"2018-11-14T08:25:53","version":"3.141.59"}, "os":{"arch":"amd64","name":"Linux","version":"4.15.0-1014-gcp"}, "java":{"version":"1.8.0_191"} } 

We are trying to execute the query /wd/hub/sessions , but we get an error 500 :

 [chimp][session-manager] requesting sessions from http://localhost:40002/wd/hub/sessions [chimp][session-manager] received error Server Error [500] [chimp][session-manager] response { "sessionId": null, "status": 13, "value": { "class": "org.openqa.grid.common.exception.GridException", "error": "unknown error", "message": "Session [(null externalkey)] not available and is not among the last 1000 terminated sessions.\nActive sessions are[]", "stackTrace": [ { "className": "org.openqa.grid.internal.ActiveTestSessions", "fileName": "ActiveTestSessions.java", "lineNumber": 120, "methodName": "getExistingSession" }, { "className": "org.openqa.grid.internal.DefaultGridRegistry", "fileName": "DefaultGridRegistry.java", "lineNumber": 387, "methodName": "getExistingSession" }, { "className": "org.openqa.grid.web.servlet.handler.RequestHandler", "fileName": "RequestHandler.java", "lineNumber": 241, "methodName": "getSession" }, { "className": "org.openqa.grid.web.servlet.handler.RequestHandler", "fileName": "RequestHandler.java", "lineNumber": 123, "methodName": "process" }, { "className": "org.openqa.grid.web.servlet.DriverServlet", "fileName": "DriverServlet.java", "lineNumber": 85, "methodName": "process" }, { "className": "org.openqa.grid.web.servlet.DriverServlet", "fileName": "DriverServlet.java", "lineNumber": 63, "methodName": "doGet" }, { "className": "javax.servlet.http.HttpServlet", "fileName": "HttpServlet.java", "lineNumber": 687, "methodName": "service" }, { "className": "javax.servlet.http.HttpServlet", "fileName": "HttpServlet.java", "lineNumber": 790, "methodName": "service" }, { "className": "org.seleniumhq.jetty9.servlet.ServletHolder", "fileName": "ServletHolder.java", "lineNumber": 865, "methodName": "handle" }, { "className": "org.seleniumhq.jetty9.servlet.ServletHandler", "fileName": "ServletHandler.java", "lineNumber": 535, "methodName": "doHandle" }, { "className": "org.seleniumhq.jetty9.server.handler.ScopedHandler", "fileName": "ScopedHandler.java", "lineNumber": 146, "methodName": "handle" }, { "className": "org.seleniumhq.jetty9.security.SecurityHandler", "fileName": "SecurityHandler.java", "lineNumber": 548, "methodName": "handle" }, { "className": "org.seleniumhq.jetty9.server.handler.HandlerWrapper", "fileName": "HandlerWrapper.java", "lineNumber": 132, "methodName": "handle" }, { "className": "org.seleniumhq.jetty9.server.handler.ScopedHandler", "fileName": "ScopedHandler.java", "lineNumber": 257, "methodName": "nextHandle" }, { "className": "org.seleniumhq.jetty9.server.session.SessionHandler", "fileName": "SessionHandler.java", "lineNumber": 1595, "methodName": "doHandle" }, { "className": "org.seleniumhq.jetty9.server.handler.ScopedHandler", "fileName": "ScopedHandler.java", "lineNumber": 255, "methodName": "nextHandle" }, { "className": "org.seleniumhq.jetty9.server.handler.ContextHandler", "fileName": "ContextHandler.java", "lineNumber": 1340, "methodName": "doHandle" }, { "className": "org.seleniumhq.jetty9.server.handler.ScopedHandler", "fileName": "ScopedHandler.java", "lineNumber": 203, "methodName": "nextScope" }, { "className": "org.seleniumhq.jetty9.servlet.ServletHandler", "fileName": "ServletHandler.java", "lineNumber": 473, "methodName": "doScope" }, { "className": "org.seleniumhq.jetty9.server.session.SessionHandler", "fileName": "SessionHandler.java", "lineNumber": 1564, "methodName": "doScope" }, { "className": "org.seleniumhq.jetty9.server.handler.ScopedHandler", "fileName": "ScopedHandler.java", "lineNumber": 201, "methodName": "nextScope" }, { "className": "org.seleniumhq.jetty9.server.handler.ContextHandler", "fileName": "ContextHandler.java", "lineNumber": 1242, "methodName": "doScope" }, { "className": "org.seleniumhq.jetty9.server.handler.ScopedHandler", "fileName": "ScopedHandler.java", "lineNumber": 144, "methodName": "handle" }, { "className": "org.seleniumhq.jetty9.server.handler.HandlerWrapper", "fileName": "HandlerWrapper.java", "lineNumber": 132, "methodName": "handle" }, { "className": "org.seleniumhq.jetty9.server.Server", "fileName": "Server.java", "lineNumber": 503, "methodName": "handle" }, { "className": "org.seleniumhq.jetty9.server.HttpChannel", "fileName": "HttpChannel.java", "lineNumber": 364, "methodName": "handle" }, { "className": "org.seleniumhq.jetty9.server.HttpConnection", "fileName": "HttpConnection.java", "lineNumber": 260, "methodName": "onFillable" }, { "className": "org.seleniumhq.jetty9.io.AbstractConnection$ReadCallback", "fileName": "AbstractConnection.java", "lineNumber": 305, "methodName": "succeeded" }, { "className": "org.seleniumhq.jetty9.io.FillInterest", "fileName": "FillInterest.java", "lineNumber": 103, "methodName": "fillable" }, { "className": "org.seleniumhq.jetty9.io.ChannelEndPoint$2", "fileName": "ChannelEndPoint.java", "lineNumber": 118, "methodName": "run" }, { "className": "org.seleniumhq.jetty9.util.thread.strategy.EatWhatYouKill", "fileName": "EatWhatYouKill.java", "lineNumber": 333, "methodName": "runTask" }, { "className": "org.seleniumhq.jetty9.util.thread.strategy.EatWhatYouKill", "fileName": "EatWhatYouKill.java", "lineNumber": 310, "methodName": "doProduce" }, { "className": "org.seleniumhq.jetty9.util.thread.strategy.EatWhatYouKill", "fileName": "EatWhatYouKill.java", "lineNumber": 168, "methodName": "tryProduce" }, { "className": "org.seleniumhq.jetty9.util.thread.strategy.EatWhatYouKill", "fileName": "EatWhatYouKill.java", "lineNumber": 126, "methodName": "run" }, { "className": "org.seleniumhq.jetty9.util.thread.ReservedThreadExecutor$ReservedThread", "fileName": "ReservedThreadExecutor.java", "lineNumber": 366, "methodName": "run" }, { "className": "org.seleniumhq.jetty9.util.thread.QueuedThreadPool", "fileName": "QueuedThreadPool.java", "lineNumber": 765, "methodName": "runJob" }, { "className": "org.seleniumhq.jetty9.util.thread.QueuedThreadPool$2", "fileName": "QueuedThreadPool.java", "lineNumber": 683, "methodName": "run" }, { "className": "java.lang.Thread", "fileName": "Thread.java", "lineNumber": 748, "methodName": "run" } ], "stacktrace": "org.openqa.grid.common.exception.GridException: Session [(null externalkey)] not available and is not among the last 1000 terminated sessions.\nActive sessions are[]\n\tat org.openqa.grid.internal.ActiveTestSessions.getExistingSession(ActiveTestSessions.java:120)\n\tat org.openqa.grid.internal.DefaultGridRegistry.getExistingSession(DefaultGridRegistry.java:387)\n\tat org.openqa.grid.web.servlet.handler.RequestHandler.getSession(RequestHandler.java:241)\n\tat org.openqa.grid.web.servlet.handler.RequestHandler.process(RequestHandler.java:123)\n\tat org.openqa.grid.web.servlet.DriverServlet.process(DriverServlet.java:85)\n\tat org.openqa.grid.web.servlet.DriverServlet.doGet(DriverServlet.java:63)\n\tat javax.servlet.http.HttpServlet.service(HttpServlet.java:687)\n\tat javax.servlet.http.HttpServlet.service(HttpServlet.java:790)\n\tat org.seleniumhq.jetty9.servlet.ServletHolder.handle(ServletHolder.java:865)\n\tat org.seleniumhq.jetty9.servlet.ServletHandler.doHandle(ServletHandler.java:535)\n\tat org.seleniumhq.jetty9.server.handler.ScopedHandler.handle(ScopedHandler.java:146)\n\tat org.seleniumhq.jetty9.security.SecurityHandler.handle(SecurityHandler.java:548)\n\tat org.seleniumhq.jetty9.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)\n\tat org.seleniumhq.jetty9.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:257)\n\tat org.seleniumhq.jetty9.server.session.SessionHandler.doHandle(SessionHandler.java:1595)\n\tat org.seleniumhq.jetty9.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:255)\n\tat org.seleniumhq.jetty9.server.handler.ContextHandler.doHandle(ContextHandler.java:1340)\n\tat org.seleniumhq.jetty9.server.handler.ScopedHandler.nextScope(ScopedHandler.java:203)\n\tat org.seleniumhq.jetty9.servlet.ServletHandler.doScope(ServletHandler.java:473)\n\tat org.seleniumhq.jetty9.server.session.SessionHandler.doScope(SessionHandler.java:1564)\n\tat org.seleniumhq.jetty9.server.handler.ScopedHandler.nextScope(ScopedHandler.java:201)\n\tat org.seleniumhq.jetty9.server.handler.ContextHandler.doScope(ContextHandler.java:1242)\n\tat org.seleniumhq.jetty9.server.handler.ScopedHandler.handle(ScopedHandler.java:144)\n\tat org.seleniumhq.jetty9.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)\n\tat org.seleniumhq.jetty9.server.Server.handle(Server.java:503)\n\tat org.seleniumhq.jetty9.server.HttpChannel.handle(HttpChannel.java:364)\n\tat org.seleniumhq.jetty9.server.HttpConnection.onFillable(HttpConnection.java:260)\n\tat org.seleniumhq.jetty9.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:305)\n\tat org.seleniumhq.jetty9.io.FillInterest.fillable(FillInterest.java:103)\n\tat org.seleniumhq.jetty9.io.ChannelEndPoint$2.run(ChannelEndPoint.java:118)\n\tat org.seleniumhq.jetty9.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:333)\n\tat org.seleniumhq.jetty9.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:310)\n\tat org.seleniumhq.jetty9.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:168)\n\tat org.seleniumhq.jetty9.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:126)\n\tat org.seleniumhq.jetty9.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:366)\n\tat org.seleniumhq.jetty9.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:765)\n\tat org.seleniumhq.jetty9.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:683)\n\tat java.lang.Thread.run(Thread.java:748)\n" } } 

What could be the problem with the /wd/hub/sessions request?
For all other requests, incl. on /wd/hub/session , this server responds normally.