Keyboard shotcuts not working etc...

[tenfoot]

Using Sparky v5.0 and Lenovo thinkpad T450s

I have been unable to access the ControlPanel on my Lenovo Thinkpad T450s for several days. In addition, none of my keyboard shortcuts worked.  So, this morning, I started to investigate and found that several mate files were not installed, so I installed them.  Unfortunately, I did not note the names of these at the time, but I think there were three, possibly mate-control-center-common, libmate-window-settings1 and one other whose name I cannot remember.

Delighted to say, that after the installation of the missing files, I can now access the Control center and all keyboard shortcuts work.

Is anyone able to suggest what update, if any, could have caused this uninstallation of necessary files?