happened with a qt5 application using gtk theme on Ubuntu MATE
$ ./my-application
Gtk-Message: Failed to load module "canberra-gtk-module"
Gtk-Message: Failed to load module "topmenu-gtk-module"
let's locate the libs
$ locate libcanberra-gtk-module.so
/usr/lib/x86_64-linux-gnu/gtk-2.0/modules/libcanberra-gtk-module.so
/usr/lib/x86_64-linux-gnu/gtk-3.0/modules/libcanberra-gtk-module.so
setting the LD_LIBRARY_PATH solves the issue
$ LD_LIBRARY_PATH=/usr/lib/x86_64-linux-gnu/gtk-3.0/modules:$LD_LIBRARY_PATH ./my-application
or unset the GTK_MODULES environment variable
$ unset GTK_MODULES; ./my-application