This same message also appears in ubntu-mate 16.04 during shut down. Not sure why it is happening. I closed all foreground applications I had running on the desktop. I finished updating the system using the GUI Software Updater tool, then played a few rounds of PySol solitaire. After finishing that game, I exited the PySol app. I then attempted to shutdown and got the message that the desktop is not responding referenced above. Wondering if it is a long-standing issue with Mate specifically. I have not seen that with earlier versions running Unity or LXE desktops.
This same message also appears in ubntu-mate 16.04 during shut down. Not sure why it is happening. I closed all foreground applications I had running on the desktop. I finished updating the system using the GUI Software Updater tool, then played a few rounds of PySol solitaire. After finishing that game, I exited the PySol app. I then attempted to shutdown and got the message that the desktop is not responding referenced above. Wondering if it is a long-standing issue with Mate specifically. I have not seen that with earlier versions running Unity or LXE desktops.