tkinterdnd2 file drag into Gtk3 apps like Nautilus does nothing. The issue is that Gtk3 based apps get the file list in the drop callback by calling data.get_uris() which returns an empty list when the drop source is tkinterdnd2 based. I know that the basic operation is correct because the file name in the Gtk app can be obtained by calling data.get_data(). The problem appears to be how to configure the tkinterdnd2 drag source so that the file list payload can be obtained from data.get_uris() in the Gtk app. The issue is demonstrated with the following apps. If you drag the file from the trkinter source app into the Gtk drop app you will messages to stdout indicating that the transfer was received as a string but not as a uri-list.