Comment 0 for bug 1742000

Thunderbird used to respect the larger system font size set in my GTK theme (can't remember what I used to set it), however after a recent update it has gone back to default which on my monitor is unreadable. This affects the applications UI dialogs such as the sidebar and list of mail on the selected account, emails themselves are displayed correctly using the minimum font size set through edit -> preferences -> display -> advanced.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: thunderbird 1:52.5.0+build1-0ubuntu0.16.04.1
ProcVersionSignature: Ubuntu 4.4.0-104.127-generic 4.4.98
Uname: Linux 4.4.0-104-generic x86_64
AddonCompatCheckDisabled: False
ApportVersion: 2.20.1-0ubuntu2.15
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/pcmC0D0p: a 1998 F...m pulseaudio
 /dev/snd/controlC0: a 1998 F.... pulseaudio
                      a 6004 F.... alsamixer
 /dev/snd/seq: a 21146 F.... lmms
BuildID: 20171122155701
Channel: Unavailable
Date: Mon Jan 8 22:47:07 2018
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 2016-06-25 (562 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
IpRoute:
 default via 192.168.1.254 dev enp1s0 proto static metric 100
 169.254.0.0/16 dev enp1s0 scope link metric 1000
 192.168.1.0/24 dev enp1s0 proto kernel scope link src 192.168.1.114 metric 100
IwConfig:
 lo no wireless extensions.

 enp1s0 no wireless extensions.
Locales: extensions.sqlite corrupt or missing
Plugins: Shockwave Flash - /usr/lib/flashplugin-installer/libflashplayer.so
PrefSources:
 prefs.js
 [Profile]/extensions/{a62ef8ec-5fdc-40c2-873c-223b8a6925cc}/defaults/preferences/preferences.js
 [Profile]/extensions/{e2fda1a4-762b-4020-b5ad-a41df1933103}/defaults/preferences/lightning.js
Profiles: Profile0 (Default) - LastVersion=52.5.0/20171122155701 (In use)
RfKill:

RunningIncompatibleAddons: False
SourcePackage: thunderbird
Themes: extensions.sqlite corrupt or missing
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 06/24/2014
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: F7
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: F2A88XM-DS2
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.board.version: x.x
dmi.chassis.asset.tag: 7385307-008
dmi.chassis.type: 3
dmi.chassis.vendor: NOVATECH LTD
dmi.chassis.version: V1.0
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrF7:bd06/24/2014:svnNOVATECHLTD:pnMBB-53004C:pvrV1.0:rvnGigabyteTechnologyCo.,Ltd.:rnF2A88XM-DS2:rvrx.x:cvnNOVATECHLTD:ct3:cvrV1.0:
dmi.product.name: MBB-53004C
dmi.product.version: V1.0
dmi.sys.vendor: NOVATECH LTD