How to Unlock Articles for Editing in Joomla Site
When a User edits a file, Joomla changes the file’s status to Checked Out (represented by the padlock icon). The file is locked and only the User who has checked it out can edit it. This is a safety/security feature that prevents two Users from modifying an Item at the same time and. Thus there will no the loss of any data upon saving.
A Content Item remains Checked Out until the User clicks Apply, Save or Cancel. Once saved, status of the Content Item changes to Checked In. But when the User clicks the Back button within his browser, or they choose another Menu Item without saving or cancelling the work in progress, or there is a connection error, the status of the Content Item remains Checked Out. No one else can edit it since that.
Global Checkin can unlock all Items in your site that are Checked Out now. Only Super Administrator can use the Global Checkin. The action starts as soon as the Menu Item is clicked.
Joomla issues a list showing how many items, and from which tables, were checked back in.
WARNING: Performing a Global Checkin while documents are open for editing will result in data loss. All Checked Out Items will be checked in, and any unsaved changes will be lost.