Please open a terminal and run
mate-panel --reset if that does not work run
mate-menu --clean & mate-menu --clear & mate-menu --reset
to revert the menu config file to it's original state.
You can find a copy in
Now I couldn't find a good way to avoid rebooting, to restart the desktop environment.
What I found indicated to either kill your X or light-dm application to reboot desktop environment.
If you still do not have the menu visible please share what is in your
/etc/xdg/menus/mate-applications.menu file as well as any output.
Please report if this issue exists if you create an other user and log into mate as the new user.
As a temp work around you can try
brisk-menu, which comes highly recommended as a mate menu.
The Min Max window error is directly related to marco,