Firstly would you mind carrying out the following steps, please, because the use of something other than an adaptive behaviour is the usual and common cause of that error.
Navigate to the category containing your question in the Question Bank, then:
- Click the Preview icon for that question (magnifying glass)
- Scroll down to the Attempt options section
- Select "Adaptive mode" in the How questions behave dropdown.
- Click Start again with these options [did you miss this step, perhaps?]
- When the page refreshes, enter your answer in the question answer box.
- Click Check.
The wording of the error message is from a slightly older version of CodeRunner. I'd suggest you upgrade to the latest version. In fact, if you don't mind living slightly closer to the bleeding edge, you could checkout the Development branch on Github, rather than the Master Branch. The Development branch is now the Version 3.1 Release Candidate, and is pretty stable. We're running it on our production systems. It has a few nice new features including a Preview
capability and an option to reload the student's answer box with a skeleton answer or extra instructions. Also, version 3.1 forces use of Adaptive Behaviour no matter what behaviour is chosen for the quiz, so the problem you're having (I think) shouldn't occur in future.