I am using beamer and I am getting error "dsfont.sty". I do not know how to solve that. I am using Ubuntu 18.04 and Kile. I appreciate your assistance in this regard.
This file is contained in
texlive-fonts-extra package (see search results on packages.ubuntu.com for reference).
So you need to install the package:
sudo add-apt-repository universe sudo apt-get install texlive-fonts-extra