Update Mate DE from 1.16 to 1.18 on Mate16.04

Hi all, I’m trying to upgrade the desktop environment of my Mate 16.04 to 1.18.
After the installation I get errors with gtk:
(mate-control-center:5974): Gtk-ERROR **: GTK+ 2.x symbols detected. Using GTK+ 2.x and GTK+ 3 in the same process is not supported

This happened opening mate-control-center or mate-appearance-properties.
Now, I downgraded to 1.16, but I like the new graphics of the 1.18 version