I too have this problem. It seems that if you go into your .thunderbird directory and delete the file addonStartup.json.lz4, thunderbird is able to start. Restarting tb usually causes the error to appearagain, but re- deleting this file allows it to start again.
-- 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/1901829 Title: thunderbird fails to open, xml parse error Status in thunderbird package in Ubuntu: Confirmed Status in thunderbird source package in Groovy: New Bug description: launching thunderbird opens a small browser window displaying the following error: XML Parsing Error: undefined entity Location: chrome://messenger/content/messenger.xhtml Line Number 905, Column 3: <key id="openLightningKey" --^ when launched from the command line, the following errors appear: [calBackendLoader] Using Thunderbird's libical backend Extension error: Error while loading 'jar:file:///usr/lib/thunderbird/extensions/messagingm...@mozilla.com.xpi!/manifest.json' (NS_ERROR_FILE_NOT_FOUND) resource://gre/modules/Extension.jsm:570 :: readJSON/</<@resource://gre/modules/Extension.jsm:570:20 onStopRequest@resource://gre/modules/NetUtil.jsm:128:18 Extension error: Error while loading 'jar:file:///usr/lib/thunderbird/omni.ja!/chrome/messenger/search-extensions/twitter/manifest.json' (NS_ERROR_FILE_NOT_FOUND) resource://gre/modules/Extension.jsm:570 :: readJSON/</<@resource://gre/modules/Extension.jsm:570:20 onStopRequest@resource://gre/modules/NetUtil.jsm:128:18 from desktop GUI it is possible to launch "Compose new message" or "Contacts" window, then in "Help" menu select "Restart with add-ons disabled", then the normal mail/calendar window opens and functions normally cheers ProblemType: Bug DistroRelease: Ubuntu 20.10 Package: thunderbird 1:78.3.2+build1-0ubuntu1 ProcVersionSignature: Ubuntu 5.8.0-25.26-generic 5.8.14 Uname: Linux 5.8.0-25-generic x86_64 AddonCompatCheckDisabled: False ApportVersion: 2.20.11-0ubuntu50 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: frankland 7570 F.... pulseaudio /dev/snd/controlC1: frankland 7570 F.... pulseaudio BuildID: 20201006011220 CasperMD5CheckResult: skip Channel: Unavailable CurrentDesktop: ubuntu:GNOME Date: Wed Oct 28 10:05:04 2020 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 2018-03-28 (945 days ago) InstallationMedia: Ubuntu 17.10 "Artful Aardvark" - Release amd64 (20180105.1) IpRoute: default via 193.48.109.1 dev enx9cebe86f11b0 proto dhcp metric 100 default via 193.48.109.1 dev wlp1s0 proto dhcp metric 600 169.254.0.0/16 dev enx9cebe86f11b0 scope link metric 1000 193.48.109.0/24 dev enx9cebe86f11b0 proto kernel scope link src 193.48.109.26 metric 100 193.48.109.0/24 dev wlp1s0 proto kernel scope link src 193.48.109.26 metric 600 Locales: extensions.sqlite corrupt or missing PrefErrors: Unexpected character ',' before close parenthesis @ /usr/lib/thunderbird/omni.ja:greprefs.js:732 PrefSources: prefs.js Profiles: Profile0 (Default) - LastVersion=78.3.2/20201006011220 (In use) RunningIncompatibleAddons: False SourcePackage: thunderbird Themes: extensions.sqlite corrupt or missing UpgradeStatus: Upgraded to groovy on 2020-10-23 (4 days ago) dmi.bios.date: 01/07/2020 dmi.bios.release: 1.17 dmi.bios.vendor: Dell Inc. dmi.bios.version: 1.17.1 dmi.board.name: 0DW6V0 dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.type: 10 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvr1.17.1:bd01/07/2020:br1.17:svnDellInc.:pnLatitude5580:pvr:rvnDellInc.:rn0DW6V0:rvrA00:cvnDellInc.:ct10:cvr: dmi.product.family: Latitude dmi.product.name: Latitude 5580 dmi.product.sku: 07D1 dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/thunderbird/+bug/1901829/+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
