Description of problem: I have inspected the internal classes responsible for actual execution of Test Scenarios and noticed that whenever it is necessary to create a KieSession only Stateful will be created. So supplying a Stateless KieSession is simply not allowed - it will fail with this error message: Test scenario runner could not find a stateful knowledge session with the name 'defaultSession'. Version-Release number of selected component (if applicable): BRMS 6.2.0 BPM Suite 6.2.0 How reproducible: always Steps to Reproduce: 1. Define Stateless session in business-central or directly in kmodule.xml 2. Configure Test Scenario with it 3. Run it Actual results: Test Scenarios can be configured only with Stateful session. Expected results: Test Scenarios can be configured with both, Stateful and Stateless sessions Additional info: Only Stateful is created https://github.com/droolsjbpm/kie-wb-common/blob/6.3.x/kie-wb-common-services/kie-wb-common-services-backend/src/main/java/org/kie/workbench/common/services/backend/session/SessionServiceImpl.java#L54
This is because the test scenarios can only be used with stateful sessions. Workaround is to make a stateful session for testing, but this is not ideal because then your not testing with the session that is used in production.