mozilla does not play sound from videos. this happened after most recent update

after most recent software update sound from videos in mozilla do not work. I have not tried any other web browsers. sound from kodi does work.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: firefox 52.0+build2-0ubuntu0.16.04.1
ProcVersionSignature: Ubuntu 4.4.0-66.87-generic 4.4.44
Uname: Linux 4.4.0-66-generic i686
AddonCompatCheckDisabled: False
ApportVersion: 2.20.1-0ubuntu2.5
Architecture: i386
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: wayne 1234 F.... lxpanel
BuildID: 20170303012758
Channel: Unavailable
CurrentDesktop: LXDE
Date: Sat Mar 11 20:03:52 2017
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)
InstallationDate: Installed on 2016-10-19 (144 days ago)
InstallationMedia: Lubuntu 16.04.1 LTS "Xenial Xerus" - Release i386 (20160720)
IpRoute:
 default via 192.168.1.1 dev wlan0 proto static metric 600
 192.168.1.0/24 dev wlan0 proto kernel scope link src 192.168.1.169 metric 600
Locales: extensions.sqlite corrupt or missing
Plugins: Shockwave Flash - /usr/lib/flashplugin-installer/libflashplayer.so
PrefSources: prefs.js
ProcEnviron:
 LANGUAGE=en_US
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
Profiles: Profile0 (Default) - LastVersion=52.0/20170303012758 (In use)
RunningIncompatibleAddons: False
SourcePackage: firefox
Themes: extensions.sqlite corrupt or missing
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 09/13/2007
dmi.bios.vendor: Hewlett-Packard
dmi.bios.version: F.08
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: 30D9
dmi.board.vendor: Hewlett-Packard
dmi.board.version: 83.19
dmi.chassis.type: 10
dmi.chassis.vendor: Hewlett-Packard
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnHewlett-Packard:bvrF.08:bd09/13/2007:svnHewlett-Packard:pnPresarioC700NotebookPC:pvrF.08:rvnHewlett-Packard:rn30D9:rvr83.19:cvnHewlett-Packard:ct10:cvrN/A:
dmi.product.name: Presario C700 Notebook PC
dmi.product.version: F.08
dmi.sys.vendor: Hewlett-Packard