Install gir1.2-messagingmenu-1.0 by entering the following commands in the terminal:
sudo apt update sudo apt install gir1.2-messagingmenu-1.0
Description:
Messaging Menu - gir bindings
. This package can be used by other packages using the GIRepository format to generate dynamic bindings.
Homepage: https://launchpad.net/indicator-messages
Version: 13.10.1+17.04.20170120-0ubuntu2
Section: introspection