I ran into this myself. From the above it looks like you use apparmor too so it's probably the same problem I had---Firefox uses GStreamer and 15.10 shipped a new version which changes the path. Try running your browser unconfined to see if it fixes the problem and then use complain mode to identify which files you need to give it access to. For me it was these:
/usr/lib/x86_64-linux-gnu/gstreamer1.0/gstreamer-1.0/gst-plugin-scanner /home/myuser/.cache/gstreamer-1.0/registry.x86_64.bin -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to firefox in Ubuntu. https://bugs.launchpad.net/bugs/1521789 Title: firefox freezes with GStreamer-WARNING **: External plugin loader failed. Status in firefox package in Ubuntu: Confirmed Bug description: firefox freezes ProblemType: Bug DistroRelease: Ubuntu 15.10 Package: firefox 42.0+build2-0ubuntu0.15.10.1 ProcVersionSignature: Ubuntu 4.2.0-19.23-generic 4.2.6 Uname: Linux 4.2.0-19-generic x86_64 AddonCompatCheckDisabled: False ApportVersion: 2.19.1-0ubuntu5 Architecture: amd64 BuildID: 20151030083518 Channel: Unavailable CurrentDesktop: Unity Date: Tue Dec 1 17:55:35 2015 ExecutablePath: /usr/lib/firefox/firefox Extensions: extensions.sqlite corrupt or missing ForcedLayersAccel: False IfupdownConfig: # interfaces(5) file used by ifup(8) and ifdown(8) auto lo iface lo inet loopback IncompatibleExtensions: Unavailable (corrupt or non-existant compatibility.ini or extensions.sqlite) IpRoute: default via 10.128.128.128 dev wlan0 proto static metric 600 10.0.0.0/8 dev wlan0 proto kernel scope link src 10.194.251.198 metric 600 169.254.0.0/16 dev wlan0 scope link metric 1000 Locales: extensions.sqlite corrupt or missing Plugins: iTunes Application Detector - /usr/lib/mozilla/plugins/librhythmbox-itms-detection-plugin.so (rhythmbox-mozilla) Shockwave Flash - /usr/lib/flashplugin-installer/libflashplayer.so PrefSources: prefs.js ProcAttrCurrent: /usr/lib/firefox/firefox{,*[^s][^h]} (enforce) Profiles: Profile0 (Default) - LastVersion=42.0/20151030083518 PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: Home directory not accessible: Permission denied No PulseAudio daemon running, or not running as session daemon. RunningIncompatibleAddons: False SourcePackage: firefox Themes: extensions.sqlite corrupt or missing UpgradeStatus: Upgraded to wily on 2015-11-22 (9 days ago) dmi.bios.date: 06/23/2014 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 1.03.05RS761 dmi.board.asset.tag: Tag 12345 dmi.board.name: Gazelle Professional dmi.board.vendor: System76, Inc. dmi.board.version: gazp9b dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 9 dmi.chassis.vendor: System76, Inc. dmi.chassis.version: gazp9b dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1.03.05RS761:bd06/23/2014:svnSystem76,Inc.:pnGazelleProfessional:pvrgazp9b:rvnSystem76,Inc.:rnGazelleProfessional:rvrgazp9b:cvnSystem76,Inc.:ct9:cvrgazp9b: dmi.product.name: Gazelle Professional dmi.product.version: gazp9b dmi.sys.vendor: System76, Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1521789/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
