Katalon Plugin throws java.lang.NullPointerException


we are evaluating if we can use Katalon as part of our CI in Bamboo (version 6.8.1) and installed it with a trial license without any trouble.
A test suite of 5 simple tests (openBrowser, navigate around the website, verifyElement, closeBrowser) with different profiles runs smoothly locally.
The plugin is set up to download Katalon 6.1.5 each time (tried 6.1.0, too).

First we used a Linux remote agent, which successfully fetched the Katalon project from git and started Katalon. The first test plan was completed successfully but the second test plan always froze the agent after a “verifyElement”-call. The message that," 20% - 1/5" tests have completed was printed to the log in regular time intervalls. The agent did not react on manual stop (even after 24 hours) and had to be restarted manually by the admin.
Therefore we switched over to a Windows 10 based remote agent which fetches the project successfully from git, too, and run a test suite which only contains the single test from the first used test suite, which appeared to run successfully. But the ra is completely unable to to start Katalon as it throws a java.lang.NullPointerException every time. It does not even start the first test but returns an error message.

Excerpt from Bamboo’s log file:

simple 29-May-2019 17:21:26 Finished task ‘Checkout Default Repository’ with result: Success

simple 29-May-2019 17:21:26 Running pre-build action: VCS Version Collector

simple 29-May-2019 17:21:26 Starting task ‘Run Katalon’ of type ‘com.katalon.katalon-bamboo-plugin:test’

error 29-May-2019 17:21:26 Error occurred while running Task ‘Run Katalon(2)’ of type com.katalon.katalon-bamboo-plugin:test.

error 29-May-2019 17:21:26 java.lang.NullPointerException

error 29-May-2019 17:21:26 at com.katalon.task.KatalonTask.execute(KatalonTask.java:30)

error 29-May-2019 17:21:26 at com.atlassian.bamboo.task.TaskExecutorImpl.lambda$executeTasks$2(TaskExecutorImpl.java:317)

error 29-May-2019 17:21:26 at com.atlassian.bamboo.task.TaskExecutorImpl.executeTaskWithPrePostActions(TaskExecutorImpl.java:252)

error 29-May-2019 17:21:26 at com.atlassian.bamboo.task.TaskExecutorImpl.executeTasks(TaskExecutorImpl.java:317)

error 29-May-2019 17:21:26 at com.atlassian.bamboo.task.TaskExecutorImpl.execute(TaskExecutorImpl.java:112)

error 29-May-2019 17:21:26 at com.atlassian.bamboo.build.pipeline.tasks.ExecuteBuildTask.call(ExecuteBuildTask.java:73)

error 29-May-2019 17:21:26 at com.atlassian.bamboo.v2.build.agent.DefaultBuildAgent.executeBuildPhase(DefaultBuildAgent.java:203)

error 29-May-2019 17:21:26 at com.atlassian.bamboo.v2.build.agent.DefaultBuildAgent.build(DefaultBuildAgent.java:175)

error 29-May-2019 17:21:26 at com.atlassian.bamboo.v2.build.agent.BuildAgentControllerImpl.lambda$waitAndPerformBuild$0(BuildAgentControllerImpl.java:131)

error 29-May-2019 17:21:26 at com.atlassian.bamboo.variable.CustomVariableContextImpl.withVariableSubstitutor(CustomVariableContextImpl.java:185)

error 29-May-2019 17:21:26 at com.atlassian.bamboo.v2.build.agent.BuildAgentControllerImpl.waitAndPerformBuild(BuildAgentControllerImpl.java:125)

error 29-May-2019 17:21:26 at com.atlassian.bamboo.v2.build.agent.DefaultBuildAgent$1.run(DefaultBuildAgent.java:126)

error 29-May-2019 17:21:26 at com.atlassian.bamboo.utils.BambooRunnables$1.run(BambooRunnables.java:48)

error 29-May-2019 17:21:26 at com.atlassian.bamboo.security.ImpersonationHelper.runWith(ImpersonationHelper.java:26)

error 29-May-2019 17:21:26 at com.atlassian.bamboo.security.ImpersonationHelper.runWithSystemAuthority(ImpersonationHelper.java:17)

error 29-May-2019 17:21:26 at com.atlassian.bamboo.security.ImpersonationHelper$1.run(ImpersonationHelper.java:41)

error 29-May-2019 17:21:26 at java.lang.Thread.run(Thread.java:748)

simple 29-May-2019 17:21:26 Running post build plugin ‘Docker Container Cleanup’

simple 29-May-2019 17:21:26 Running post build plugin ‘NCover Results Collector’

simple 29-May-2019 17:21:26 Running post build plugin ‘Clover Results Collector’

simple 29-May-2019 17:21:26 Running post build plugin ‘npm Cache Cleanup’

simple 29-May-2019 17:21:26 Running post build plugin ‘Artifact Copier’

simple 29-May-2019 17:21:26 Publishing an artifact: Katalon Studio artifacts

simple 29-May-2019 17:21:31 Finished publishing of artifact Required shared artifact: [Katalon Studio artifacts], pattern: [Reports/**/.] in 4.915 s

simple 29-May-2019 17:21:31 Finalising the build…

simple 29-May-2019 17:21:31 Stopping timer.

simple 29-May-2019 17:21:31 Build BW-KT-JOB1-29 completed.

simple 29-May-2019 17:21:28 Running on server: post build plugin ‘NCover Results Collector’

simple 29-May-2019 17:21:28 Running on server: post build plugin ‘Build Hanging Detection Configuration’

simple 29-May-2019 17:21:28 Running on server: post build plugin ‘Clover Delta Calculator’

simple 29-May-2019 17:21:28 Running on server: post build plugin ‘Maven Dependencies Postprocessor’

simple 29-May-2019 17:21:28 All post build plugins have finished

simple 29-May-2019 17:21:28 Generating build results summary…

simple 29-May-2019 17:21:28 Saving build results to disk…

simple 29-May-2019 17:21:28 Logging substituted variables…

simple 29-May-2019 17:21:28 Indexing build results…

simple 29-May-2019 17:21:28 Finished building BW-KT-JOB1-29.

The Win10 agent’s capabilities:

Do you have any idea what I might be overlooking? Or any documentation regarding the Bamboo plugin apart from the Integration Document?

Thank you.