Problem with running mockserver

I am using Katalon Studio version 8.4.0 beta on Windows 10.
I am trying to use mockserver and generate a response using a callback class in one of my tests.
I am using a simple example from mockserver’s documentation (Creating Expectations):

I use the same code in a Katalon studio keyword and call it in my test script to start mock server to intercept messages

Everytime a message matches an expectation, the console log shows this exception:

When it clearly does implement ExpectationResponseCallback.

Hi Asheesh @aasheesh.jha, did you import all the necessary libraries in your code?
You can check this Github repo here that uses the same example that you used to compare your code and see if you miss anything.

I hope this helps.

Hi @chen.lee, I did import all the libraries mentioned in this example:
In the build.gradle of this project, I used implementation ‘org.mock-server:mockserver-netty:5.13.2’ dependency, which has copied the katalon_generated_mockserver-core-5.13.2.jar, katalon_generated_mockserver-client-java-5.13.2.jar and katalon_generated_mockserver-netty-5.13.2.jar into the drivers folder of the project.

Hey @aasheesh.jha, after checking with customer support. KS does not support this mock server script. You can suggest this feature here if you want it to be implemented in later releases.

It was working perfectly when I was using KS 8.2.0 and the mockserver dependency "compile ‘org.mock-server:mockserver-netty:3.10.8’ " in build.gradle.
It broke with the latest KS that I used(8.3.5 and 8.4)

Best to submit a ticket here for the Product team to examine the problem closely.