This problem is similar to others posted here, but after some searching I can't find an answer, and no one has asked exactly this question as far as I can see.
I upgraded a VM (VMware) to Ubuntu 16.04 LTS and installed the MATE desktop. I now see that some applications, such as Evolution and Chrome, have no menubar, and the Alt key won't display it. Firefox responds to the Alt key and displays a menu, although the default is no menubar. Others, such as Synaptic Package Manager (which runs as root) display an application menubar at all times.
MATE Terminal has no menubar, and checking "Show Menubar" has no effect. I'm running Gnome (Metacity) as an alternate desktop on the same system and have no such problem there.
I want a menubar available in every application in which one is available, by default. Is there a Gconf (or the MATE equivalent) setting which controls this? I've been playing with MATE Tweak which has crashed a few times and may have hosed some settings.
$ apt-cache policy ubuntu-mate-desktop
ubuntu-mate-desktop:
Installed: (none)
Candidate: 1.154.1
Version table:
1.154.1 500
500 http://us.archive.ubuntu.com/ubuntu xenial-updates/universe i386 Packages
1.154 500
500 http://us.archive.ubuntu.com/ubuntu xenial/universe i386 Packages
This looks like a per-user problem since a fresh user set to the MATE desktop deson't see it.