Looks like it's something wrong with my "~/.local/share/applications/mimeapps.list" config. After removing it I am able to change associations back and forth.
Attaching my old broken mimeapps.list. ** Attachment added: "mimeapps.list.copy" https://bugs.launchpad.net/ubuntu/+source/nautilus/+bug/1280794/+attachment/3983873/+files/mimeapps.list.copy -- 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: Incomplete 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