I believe the bug here is that once you use System Settings > Details > Default applications for audio or video you then cannot individually change any related mime in nautilus > properties of a a/v filetype to a new default.
Test case: delete ~/.local/share/applications/mimeapps.list Open system settings > Details > default apps.. & set the default for either audio or video to some other player (Ex. video to vlc Then right click on a related filetype > properties > open with & try to set to another player, it will not do so (ex. r. click on a .mp4, try to set to Videos ** Changed in: nautilus (Ubuntu) Status: Incomplete => New -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to nautilus in Ubuntu. https://bugs.launchpad.net/bugs/1280794 Title: Can't change default "Open with" application Status in “nautilus” package in Ubuntu: New Bug description: I am on Ubuntu 13.10 using nautilus 1:3.8.2-0ubuntu2.2. I am trying to change default application to open .avi files. I right- click an .avi file select "Properties", go to "Open With". There is a default application there (banshee) and recommended (VLC media player). I select VLC media player and click "Set as default" button, selection jumps back to banshee, "Set as default" button disabled and nothing else happens. Nautilus still opens .avi files with banshee. ProblemType: Bug DistroRelease: Ubuntu 13.10 Package: nautilus 1:3.8.2-0ubuntu2.2 ProcVersionSignature: Ubuntu 3.11.0-15.25-generic 3.11.10 Uname: Linux 3.11.0-15-generic x86_64 ApportVersion: 2.12.5-0ubuntu2.2 Architecture: amd64 Date: Sun Feb 16 21:45:45 2014 GsettingsChanges: b'org.gnome.nautilus.window-state' b'geometry' b"'1497x873+0+171'" InstallationDate: Installed on 2013-11-17 (91 days ago) InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1) MarkForUpload: True SourcePackage: nautilus UpgradeStatus: No upgrade log present (probably fresh install) mtime.conffile..etc.xdg.autostart.nautilus.autostart.desktop: 2013-11-20T19:34:55.419627 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/nautilus/+bug/1280794/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp