This question originated from and then was answered by Silvia Ines Borro, a MoodleMonthly reader.  The question was:

I’ve got in my Online Users block , a list of users that are not  really connected.  How can I close their sessions?

Here’s her answer (which she found after troubleshooting):

To remove the users from the user block, open  the mdl_user table you’ll find fields such as lastlogin…fill them with  zero.

To remove the users from the user block that appears when you are in a course open mdl_lastaccess, and locate the user id and the course id and delete that record.

That being said, do be careful when editing any mdl_user table to ensure that you don’t accidentally delete or edit any crucial user data.

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