Problem Description
This article will teach you how to solve the problem that both features Mentioning and Editing by are actually now appearing at all.
Solution
The problem is based on the fact that the user(s) either do not appear in any project or are not added to the correct ones. So, please make sure to make this configuration correctly. It could be done in Administration - Users - [select a user] - Projects tab. You may see an example screenshot below:
