The status of a user is indicated in the Enabled/Disabled column. You can change these statuses by editing the user.
If you wish to enable a Disabled user, for example, click Edit.
In the new screen, click on the checkbox next to the Enable User field and click Save.
Users who are Enabled are free to log in to the system with their active credentials; those who are Disabled do not have these same rights and cannot log in.