Hi there. I have installed Ubuntu Mate 17.10 freshly and am exploring it right now. But when I am booting my virtual machine in VirtualBox with Windows 98 and try to access the menu it just freezes and I can’t open it anymore. I am able to reset it with
setsid mate-panel --replace
but still I can’t access the menu. Is there any fix or workaround for this?
Hello,
Are you using a top-menu tweaked wm theme, like Cupertino or Mutiny ?
In that case, try another tweak that disable it when you are using Virtual Box, since top Menu is not perfect yet. I have the same problem here for Virtual Box and some other software, like Inkscape.
Thank you, that worked out for me. 
I noticed this too… had switch off from Global Menu. I’m using Redmond with some customizations (Yes, I’m used Windows in my previous life).
Even with Redmond my lower bar is “frozen”, not crashed when I’m using Virtualbox on second screen. I can’t access to menu or applications. However, when I minimize VirtualBox then Menu is working, but not example applications or shutdown button. I have to run setsid mate-panel --replace to fix this.
What I have tried to do:
-I used all compositors: Compiz, Marco, Software ect
-I have used with Intel GPU and Nvidia GPU (Optimus, Proprietary)
-I have tried latest Virtualbox 5.2.x
I’m thinking that if I should step back to Ubuntu MATE 16.04.3 LTS on this my work machine… can anyone confirm if the virtualbox is this edition causing such issues?