Having issues with jmeter sockets

Question

I'm Getting this error while executing script

Thread Name: Thread Group 1-1
Sample Start: 2019-10-30 15:58:38 PKT
Load time: 5005
Connect Time: 0
Latency: 0
Size in bytes: 0
Sent bytes:0
Headers size in bytes: 0
Body size in bytes: 0
Sample Count: 1
Error Count: 1
Data type ("text"|"bin"|""): 
Response code: 
Response message: 

[Execution Flow]
 - Opening new connection
 - Using response message pattern ""
 - Using disconnect pattern ""
 - Waiting for the server connection for 5000 MILLISECONDS
 - Cannot connect to the remote server


[Variables]
 - Message count: 0


[Problems]
 - Unexpected error: null
JMeter.plugins.functional.samplers.websocket.ServiceSocket.sendMessage(ServiceSocket.java:189)
JMeter.plugins.functional.samplers.websocket.WebSocketSampler.sample(WebSocketSampler.java:141)
org.apache.jmeter.threads.JMeterThread.executeSamplePackage(JMeterThread.java:490)
org.apache.jmeter.threads.JMeterThread.processSampler(JMeterThread.java:416)
org.apache.jmeter.threads.JMeterThread.run(JMeterThread.java:250)
java.lang.Thread.run(Unknown Source)


Response headers:


SampleResult fields:
ContentType: 
DataEncoding: UTF-8

Answer 1

Looking into ServiceSocket line 189 it appears that the session object is null, check jmeter.log file for any suspicious entries, it might be the case you plugin installation is corrupt (i.e. missing dependencies)

In general I would recommend switching to WebSocket Samplers by Peter Doornbosch which can be installed using JMeter Plugins Manager

this version is more up-to-date and has way more features.