Diem Symfony - Error The "%s" module does not exist

php symfony dmAdmin:generate --clear=CaseStudy
throw new dmException(sprintf('The "%s" module does not exist', $moduleKey));

The module naming convention is "modulized" (http://diem-project.org/diem-5-0/doc/en/reference-book/conventions#syntaxes:modulized)

You should try to rename your module to "casestudy" or "caseStudy" in your modules.yml.

And then, run
dmAdmin:generate --clear=caseStudy