Files can be restored if for some reason the link between the attachment resources and the database has been lost. Restoration is impossible if the resource has been lost completely.

If the Attachment Storage Location is set to Confluence’s local file system, the attachment resources are restored to the following locations.

(Confluence’s Attachment Storage Path) / (path for space ID) / (path for page ID) / (attachment ID) / attachment version number 

If while using Confluence, the actual location becomes inconsistent with the storage location above due to movement of pages or attachments, the file resources themselves become lost in spite of the fact that they do exist. This add-on restores them by resolving this inconsistency.