Why can't I assign a Responsible User to the Update Documents Task in a Change Request?

You do not have to assign Responsible User(s) to the Update Documents Task in a Change Request. The responsible Users are those who already have a role in the Document(s): (Author(s), Reviewer(s), Approver(s), QA(s).

If the Update Documents Task was added to the Change Request while it was in Created status then the Responsible Users will receive an email notification indicating that the Document(s) need to be updated when the Change Request reaches Implementing status.

If the Update Documents Task was added to the Change Request while it was in Implementing status then the Responsible Users will receive an email notification indicating that the Document(s) need to be updated as soon as the Task is saved.