In the docs https://flowable.com/open-source/docs/cmmn/ch08-REST/#list-of-case-instances, includecaseVariables should be includeCaseVariables. The difference in case might not be obvious to new comers like me; and needless to say “includecaseVariables” does not work; “includeCaseVariables” works.
Thanks for reporting the issue. I’ve submitted the following pull request to fix the documentation issue.
The PR was merged. The issue can be marked solved.