Update for UbuntuMATE 16.04.6 broke the GUI

[Bret Busby]

Hello.

A few hours ago, I performed a system update on one of my UbuntuMATE
16.04.6 systems, and it has broken the system.

The panel in the GUI is broken, and the taskbar has been eliminated,
by the update, rendering the GUI unusable.

Is it possible to reverse the system update?

-- 
Bret Busby
Armadale
West Australia
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"So once you do know what the question actually is,
 you'll know what the answer means."
- Deep Thought,
 Chapter 28 of Book 1 of
 "The Hitchhiker's Guide to the Galaxy:
 A Trilogy In Four Parts",
 written by Douglas Adams,
 published by Pan Books, 1992

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