kloadgen: setSchemaRegistryProperties method exception

I got this issue

net.coru.kloadgen.config.schemaregistry.SchemaRegistryConfigElement#setSchemaRegistryProperties(LinkedList [PropertyMapping(propertyName=schema.registry.auth.enabled, propertyValue=NO), PropertyMapping(propertyName=schema.registry.auth.method, propertyValue=BASIC), PropertyMapping(propertyName=schema.registry.username, propertyValue=<username>), PropertyMapping(propertyName=schema.registry.password, propertyValue=<password>), PropertyMapping(propertyName=schema.registry.bearer, propertyValue=<bearer>)]

and this is the detail.

java.lang.Error: This should never happen. Tried to invoke:
net.coru.kloadgen.config.schemaregistry.SchemaRegistryConfigElement#setSchemaRegistryProperties(LinkedList [PropertyMapping(propertyName=schema.registry.auth.enabled, propertyValue=NO), PropertyMapping(propertyName=schema.registry.auth.method, propertyValue=BASIC), PropertyMapping(propertyName=schema.registry.username, propertyValue=<username>), PropertyMapping(propertyName=schema.registry.password, propertyValue=<password>), PropertyMapping(propertyName=schema.registry.bearer, propertyValue=<bearer>)] )
	at org.apache.jmeter.testbeans.TestBeanHelper.invokeOrBailOut(TestBeanHelper.java:169) ~[ApacheJMeter_core.jar:5.2.1]
	at org.apache.jmeter.testbeans.TestBeanHelper.prepare(TestBeanHelper.java:97) ~[ApacheJMeter_core.jar:5.2.1]
	at org.apache.jmeter.threads.TestCompiler.trackIterationListeners(TestCompiler.java:183) ~[ApacheJMeter_core.jar:5.2.1]
	at org.apache.jmeter.threads.TestCompiler.subtractNode(TestCompiler.java:137) ~[ApacheJMeter_core.jar:5.2.1]
	at org.apache.jorphan.collections.HashTree.traverseInto(HashTree.java:998) ~[jorphan.jar:5.2.1]
	at org.apache.jorphan.collections.HashTree.traverseInto(HashTree.java:995) ~[jorphan.jar:5.2.1]
	at org.apache.jorphan.collections.HashTree.traverse(HashTree.java:977) ~[jorphan.jar:5.2.1]
	at org.apache.jmeter.threads.JMeterThread.initRun(JMeterThread.java:703) ~[ApacheJMeter_core.jar:5.2.1]
	at org.apache.jmeter.threads.JMeterThread.run(JMeterThread.java:253) ~[ApacheJMeter_core.jar:5.2.1]
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_252]
Caused by: java.lang.reflect.InvocationTargetException
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_252]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_252]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_252]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_252]
	at org.apache.jmeter.testbeans.TestBeanHelper.invokeOrBailOut(TestBeanHelper.java:167) ~[ApacheJMeter_core.jar:5.2.1]
	... 9 more
Caused by: java.lang.NullPointerException
	at java.util.Hashtable.put(Hashtable.java:460) ~[?:1.8.0_252]
	at java.util.Properties.setProperty(Properties.java:166) ~[?:1.8.0_252]
	at net.coru.kloadgen.config.schemaregistry.SchemaRegistryConfigElement.serializeProperties(SchemaRegistryConfigElement.java:58) ~[kloadgen-1.2.0.jar:?]
	at net.coru.kloadgen.config.schemaregistry.SchemaRegistryConfigElement.setSchemaRegistryProperties(SchemaRegistryConfigElement.java:45) ~[kloadgen-1.2.0.jar:?]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_252]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_252]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_252]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_252]
	at org.apache.jmeter.testbeans.TestBeanHelper.invokeOrBailOut(TestBeanHelper.java:167) ~[ApacheJMeter_core.jar:5.2.1]
	... 9 more

From Jmeter source

/**
     * Utility method that invokes a method and does the error handling around
     * the invocation.
     *
     * @param invokee
     *            the object on which the method should be invoked
     * @param method
     *            the method which should be invoked
     * @param params
     *            the parameters for the method
     * @return the result of the method invocation.
     */
    private static Object invokeOrBailOut(Object invokee, Method method, Object[] params) {
        try {
            return method.invoke(invokee, params);
        } catch (IllegalArgumentException | IllegalAccessException | InvocationTargetException e) {
            throw new Error(createMessage(invokee, method, params), e);
        }
    }

I guess the method invoke one of those three exceptions which is illegalArgumentException, illegalAccessException and InvocationTargetException.

What am I supposed to do with that ?