Why can't I edit a document that has been checked out?

You cannot edit the document because it has been checked out by another user who has not yet checked the document back in. This is to prevent the creation of several different copies in M-Files. With system administrator permissions, the document can be forced to be checked in, but the changes made to the document during the checkout will then be lost.

Sending a check-in request

You can also send a check-in request to the user who has checked out a document: Right-click the document and select Send Check-in Request. The user gets an email message about the request. The message also contains a link to the document. The check-in request is sent to the email address associated with the user's login account.