I tried a new build of E25, and noticed the dock has a launcher of an app which is not installed. Seems like the .order file (e/applications/bar/default/.order) is populated without checking if the application is installed or not (I have the .desktop file in the system, but the application is not installed)
Note that this is not the case of the Menus, which does deeper checks on the efreet values, so this applications is (correctly) not included in the menus even if i have the .desktop file installed. I think the menus also check for other important values like NotShowIn=X-Enlightenment;