El Capitan issue: Drag-and-Drop to open an image with the Preview.app in the Finder Toolbar not working El Capitan issue: Drag-and-Drop to open an image with the Preview.app in the Finder Toolbar is not working ... dragging an image over the preview.app icon in my finder windows toolbar it results in an forbiden icon an nothing happens ...



Any idea how to fix this?
You have to enable the option with a somewhat misleading name "spring-loading delay". It is now a component of System Preferences → Accessibility → Mouse &amp; Trackpad, see answer at Spring loaded folder settings missing in Yosemite