How do I resolve this error, NL-WEBSOCKET-CHANNEL-ENGINE?

Getting this while checking a user path:

Message: Error occurred while executing WebSocket channel. Details: java.util.concurrent.ExecutionException: org.eclipse.jetty.websocket.api.UpgradeException: Didn't switch protocols, expected status <101>, but got <404> at org.eclipse.jetty.util.FuturePromise.get(FuturePromise.java:138) at com.neotys.nl.c.b.JettyHttpClient.executeWebSocket(JettyHttpClient.java:863) at com.neotys.nl.controller.w.d.a.d.a(d.java:82) at com.neotys.nl.lg.engine.n.b(n.java:409) at com.neotys.nl.lg.engine.n.internalExecute(n.java:338) at com.neotys.nl.lg.engine.l.a(l.java:146) at com.neotys.nl.lg.engine.v.c(v.java:125) at com.neotys.nl.lg.engine.w.internalExecute(w.java:83) at com.neotys.nl.lg.engine.l.a(l.java:146) at com.neotys.nl.lg.engine.v.c(v.java:125) at com.neotys.nl.lg.engine.w.internalExecute(w.java:83) at com.neotys.nl.lg.engine.l.a(l.java:146) at com.neotys.nl.lg.engine.H.i(H.java:251) at com.neotys.nl.lg.engine.H.internalExecute(H.java:98) at com.neotys.nl.lg.engine.l.a(l.java:146) at com.neotys.nl.lg.engine.c.a(c.java:179) at com.neotys.nl.lg.engine.c.run(c.java:110) Caused by: org.eclipse.jetty.websocket.api.UpgradeException: Didn't switch protocols, expected status <101>, but got <404> at org.eclipse.jetty.websocket.client.io.UpgradeConnection.validateResponse(UpgradeConnection.java:352) at org.eclipse.jetty.websocket.client.io.UpgradeConnection.read(UpgradeConnection.java:280) at org.eclipse.jetty.websocket.client.io.UpgradeConnection.onFillable(UpgradeConnection.java:196) at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:265) at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:95) at org.eclipse.jetty.io.ssl.SslConnection.onFillable(SslConnection.java:197) at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:265) at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:95) at org.eclipse.jetty.io.SelectChannelEndPoint$2.run(SelectChannelEndPoint.java:75) at org.eclipse.jetty.util.thread.strategy.ExecuteProduceConsume.produceAndRun(ExecuteProduceConsume.java:213) at org.eclipse.jetty.util.thread.strategy.ExecuteProduceConsume.run(ExecuteProduceConsume.java:147) at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:654) at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:572) at java.lang.Thread.run(Thread.java:745)