An important thing you should do as a Redmine Administrator is to set Q&A permissions at the Roles and permissions section.
Here you can set permissions for users to:
- view, post, vote for questions and answers.
- post comments.
- edit or delete own/any messages or comments - there are separate permission settings for own messages (user is the author) and all messages.
- manage Help & Support sections.
- create new message Tags - otherwise, the user may select only between the currently existing ones.