To overcome this problem, users usually rely on an (super) administrator user action, since it’s the only user level who can access the Global Chek-in tool in the backend panel.

The main concern in this ACL rule on Joomla is that most of the times users who manage the website contents have a manager access level, since this user level is much more restricted on technical configuration’s options.

To allow Global Check-in action for managers, just edit the core file located at /libraries/joomla/users/authorization.php adding below line 91 the following code:

$this->addACL( "com_checkin", "manage", "users", "manager" );

Important: Since this is a core hack, keep in mind that it could be overwritten on further upgrades!