Just found out, that you can make Firefox play that video by pressing 'Pause' and afterwards 'Play', when it halts. I think, it looks like a timing issue in Firefox itself. Still it is very confusing for a user and I had the same problem trying to play voice maWhatsapp
-- 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/1816090 Title: Firefox does not play YouTube anymore after some update Status in firefox package in Ubuntu: New Bug description: After some update Firefox 65.0 does not play YouTube videos anymore in some virtual machines of Virtualbox 6.04. The following VM were tested and found wrong Xubuntu 18.04.2, Ubuntu Mate 18.04.2 both with Linux 4.18 and Ubuntu 16.04 with Linux 4.15. The same Firefox release does play those video correctly using real hardware with Ubuntu Mate 18.04.2 and Linux 4.15 and in the Virtual machines of Linux Mint 19.1 and Peppermint 9, both with Linux 4.15. Also the Firefox Development 66.0b7 edition has that same problem. Opera, Chrome and Chromium still do play those videos correctly in the Virtual Machines, which do not play with Firefox. On starting the YouTube video, it starts, it buffers to get the normal 2 minutes. But after a approx. 9 frames, it halts displaying the video. ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: firefox 65.0+build2-0ubuntu0.18.04.1 ProcVersionSignature: Ubuntu 4.18.0-15.16~18.04.1-generic 4.18.20 Uname: Linux 4.18.0-15-generic x86_64 AddonCompatCheckDisabled: False ApportVersion: 2.20.9-0ubuntu7.5 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: bertadmin 1776 F.... pulseaudio /dev/snd/pcmC0D0p: bertadmin 1776 F...m pulseaudio /dev/snd/timer: bertadmin 1776 f.... pulseaudio BuildID: 20190128144255 Channel: Unavailable CurrentDesktop: MATE Date: Fri Feb 15 10:55:10 2019 DefaultProfileExtensions: extensions.sqlite corrupt or missing DefaultProfileIncompatibleExtensions: Unavailable (corrupt or non-existant compatibility.ini or extensions.sqlite) DefaultProfileLocales: extensions.sqlite corrupt or missing DefaultProfilePrefSources: /usr/lib/firefox/defaults/pref/all-ubuntumate.js prefs.js DefaultProfileThemes: extensions.sqlite corrupt or missing ForcedLayersAccel: False IfupdownConfig: # interfaces(5) file used by ifup(8) and ifdown(8) auto lo iface lo inet loopback IpRoute: default via 192.168.0.1 dev enp0s3 proto dhcp metric 100 169.254.0.0/16 dev enp0s3 scope link metric 1000 192.168.0.0/24 dev enp0s3 proto kernel scope link src 192.168.0.109 metric 100 192.168.122.0/24 dev virbr0 proto kernel scope link src 192.168.122.1 linkdown Profile0Extensions: extensions.sqlite corrupt or missing Profile0IncompatibleExtensions: Unavailable (corrupt or non-existant compatibility.ini or extensions.sqlite) Profile0Locales: extensions.sqlite corrupt or missing Profile0PrefSources: /usr/lib/firefox/defaults/pref/all-ubuntumate.js prefs.js Profile0Themes: extensions.sqlite corrupt or missing Profiles: Profile0 - LastVersion=66.0/20190211185957 (Out of date) Profile1 (Default) - LastVersion=65.0/20190128144255 (In use) RunningIncompatibleAddons: False SourcePackage: firefox UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 12/01/2006 dmi.bios.vendor: innotek GmbH dmi.bios.version: VirtualBox dmi.board.name: VirtualBox dmi.board.vendor: Oracle Corporation dmi.board.version: 1.2 dmi.chassis.type: 1 dmi.chassis.vendor: Oracle Corporation dmi.modalias: dmi:bvninnotekGmbH:bvrVirtualBox:bd12/01/2006:svninnotekGmbH:pnVirtualBox:pvr1.2:rvnOracleCorporation:rnVirtualBox:rvr1.2:cvnOracleCorporation:ct1:cvr: dmi.product.family: Virtual Machine dmi.product.name: VirtualBox dmi.product.version: 1.2 dmi.sys.vendor: innotek GmbH To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1816090/+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