"Gtk-Message: 16:51:25.304: Failed to load module "canberra-gtk-module" when trying to open "atom"

When I try to run atom or sudo atom, I get this error:

Gtk-Message: 16:51:25.304: Failed to load module "canberra-gtk-module

I looked at similar posts, and they suggest installing:

sudo apt-get install libcanberra-gtk-module
sudo apt-get install libcanberra-gtk-module:i386

Even after installing them, the problem still appear.

I tried to install atom by:

sudo apt-get insatall atom

I am getting:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
atom is already the newest version (1.26.1-1~webupd8~0).
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

I also tried: wget -O atom-amd64.deb https://atom.io/download/deb

But there seem to be a problem.

--2018-09-28 17:08:21--  https://atom.io/download/deb
Resolving atom.io (atom.io)... 34.231.150.116, 34.232.181.106, 34.235.97.255, ...
Connecting to atom.io (atom.io)|34.231.150.116|:443... connected.
ERROR: cannot verify atom.io's certificate, issued by ‘CN=DigiCert SHA2 High Assurance Server CA,OU=www.digicert.com,O=DigiCert Inc,C=US’:
  Unable to locally verify the issuer's authority.
To connect to atom.io insecurely, use `--no-check-certificate'.

I do not want to use --no-check-certificate because I need authentication of the website and this is not achieved without a certificate.