During a content copy or a content edition ContentWorkflowHelper.doAction can be called several time on linked contents.
ContentWorkflowHelper.doAction set the content in request attribute but never restore the current content.
So the content in request attribut can changed several times during copy. Validator based on current content in request can failed.
For example, when copying a container content in ODF, YearsEnumerator wait for a Container but can received a Course or CourseList in request because of linked contents.