It seems if you already have the mozilla lightning extension install TB disables it but then does not see the xul version (6.2.2.1) if it is installed. Removing the mozilla version (using the button on the TB addons page) and restarting then finds the xul version and it then seems to function correctly
-- You received this bug notification because you are a member of Desktop Packages, which is subscribed to thunderbird in Ubuntu. https://bugs.launchpad.net/bugs/1798799 Title: lightning add on not compatible with latest release Status in thunderbird package in Ubuntu: Confirmed Bug description: Lightning 5.4 is disabled as it is not compatible with Thunderbird 60.2.1 I get this on two separate machines. ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: thunderbird 1:60.2.1+build1-0ubuntu0.18.04.2 ProcVersionSignature: Ubuntu 4.15.0-36.39-generic 4.15.18 Uname: Linux 4.15.0-36-generic x86_64 AddonCompatCheckDisabled: False ApportVersion: 2.20.9-0ubuntu7.4 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: tom 1853 F.... pulseaudio BuildID: 20181010142617 Channel: Unavailable CurrentDesktop: XFCE Date: Fri Oct 19 11:32:43 2018 ForcedLayersAccel: False IncompatibleExtensions: English (GB) Language Pack - langpack-en...@thunderbird.mozilla.org Thunderbird (default) - {972ce4c6-7e08-4474-a285-3208198ce6fd} IpRoute: default via 192.168.2.254 dev wlp2s0 proto dhcp metric 600 169.254.0.0/16 dev wlp2s0 scope link metric 1000 192.168.2.0/24 dev wlp2s0 proto kernel scope link src 192.168.2.64 metric 600 MostRecentCrashID: bp-80fbbbfc-d94c-4bb6-a8dc-cc6580180917 Plugins: Shockwave Flash - /usr/lib/flashplugin-installer/libflashplayer.so PrefSources: prefs.js Profiles: Profile0 (Default) - LastVersion=60.2.1/20181010142617 (In use) RunningIncompatibleAddons: True SourcePackage: thunderbird UpgradeStatus: Upgraded to bionic on 2018-09-08 (41 days ago) dmi.bios.date: 11/25/2015 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 1.05.03 dmi.board.asset.tag: Tag 12345 dmi.board.name: W65_W67RZ dmi.board.vendor: CLEVO dmi.board.version: Not Applicable dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: Notebook dmi.chassis.version: N/A dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1.05.03:bd11/25/2015:svnPCSpecialistLimited:pnW65_W67RZ:pvrNotApplicable:rvnCLEVO:rnW65_W67RZ:rvrNotApplicable:cvnNotebook:ct10:cvrN/A: dmi.product.family: Not Applicable dmi.product.name: W65_W67RZ dmi.product.version: Not Applicable dmi.sys.vendor: PC Specialist Limited To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/thunderbird/+bug/1798799/+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