Firefox menu bar cannot be enabled

[Nico Orrù]

On Xubuntu/desktop 16.10
- Menu bar appears on indicator
- Menu bar cannot be enabled in customize

This is a deal breaker. One of the main reasons why I use Firefox rather than Chrome on Linux is the menu bar.

Should I use Chrome instead?

ProblemType: Bug
DistroRelease: Ubuntu 16.10
Package: firefox 51.0.1+build2-0ubuntu0.16.10.2
ProcVersionSignature: Ubuntu 4.8.0-37.39-lowlatency 4.8.16
Uname: Linux 4.8.0-37-lowlatency x86_64
AddonCompatCheckDisabled: False
ApportVersion: 2.20.3-0ubuntu8.2
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: nico 2150 F.... pulseaudio
BuildID: 20170201174907
Channel: Unavailable
CurrentDesktop: XFCE
Date: Fri Feb 10 22:34:03 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 2016-10-20 (113 days ago)
InstallationMedia: Ubuntu 16.10 "Yakkety Yak" - Release amd64 (20161012.2)
IpRoute:
 default via 10.1.0.1 dev wifi0 proto static metric 600
 10.1.0.0/16 dev wifi0 proto kernel scope link src 10.1.8.81 metric 600
 169.254.0.0/16 dev wifi0 scope link metric 1000
Locales: extensions.sqlite corrupt or missing
Plugins:
 Google Talk Plugin Video Renderer - /opt/google/talkplugin/libnpo1d.so (google-talkplugin)
 Google Talk Plugin - /opt/google/talkplugin/libnpgoogletalk.so (google-talkplugin)
 Shockwave Flash - /usr/lib/flashplugin-installer/libflashplayer.so
PrefSources:
 prefs.js
 [Profile]/extensions/{3d7eb24f-2740-49df-8937-200b1cc08f8a}/defaults/preferences/flashblock.js
 [Profile]/<email address hidden>/defaults/preferences/prefs.js
Profiles: Profile0 (Default) - LastVersion=51.0.1/20170201174907 (In use)
RelatedPackageVersions: google-talkplugin 5.41.0.0-1
RunningIncompatibleAddons: False
SourcePackage: firefox
Themes: extensions.sqlite corrupt or missing
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 08/02/2016
dmi.bios.vendor: LENOVO
dmi.bios.version: N1FET43W (1.17 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20FBCTO1WW
dmi.board.vendor: LENOVO
dmi.board.version: SDK0J40697 WIN
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.modalias: dmi:bvnLENOVO:bvrN1FET43W(1.17):bd08/02/2016:svnLENOVO:pn20FBCTO1WW:pvrThinkPadX1Carbon4th:rvnLENOVO:rn20FBCTO1WW:rvrSDK0J40697WIN:cvnLENOVO:ct10:cvrNone:
dmi.product.name: 20FBCTO1WW
dmi.product.version: ThinkPad X1 Carbon 4th
dmi.sys.vendor: LENOVO

[Nico Orrù (nigu-orru)]

Found the solution:

about:config
ui.use_unity_menubar=false

Who thought it was a good idea to enable it by default?