If the user account was disabled and you want to reactivate/enable it again, please follow these steps:
1. Go to the Configuration tab - to User Management.
2. Find the needed user (you can use a filter for searching by name or other parameters).
3. In the filter for “Enable” choose “-----” or “No”, that will allow you to see disabled users.
4. After finding a required user, you should click on the edit button.
5. Then you will see the “Edit User” menu. There is a switcher at the bottom of the main page, and you should click on it and then on the Update button. Now your user is enabled/reactivated.