Deleted assets automaticaly come back

I´ve spent HOURS trying to delete unused assets, only to find out that they come back automaticaly when I reopen a project. How come?

Keep in mind that if you delete an asset from the Assets panel while it’s still being used somewhere in your site, that asset will show up in the Assets panel again once you publish the site and refresh the Designer. All instances of the asset must be deleted from your site, then from the Assets panel, to remove it completely.

Hi Nelson, thanks for the reply. I can´t delete those instances yet, a simple delete assets should suffice, so i decided to create a new project from scratch, that workaround made sure that i dont get old assets on the images folder whenever I export a ´new project.