Install elpa-pdf-tools-server by entering the following commands in the terminal:
sudo apt update sudo apt install elpa-pdf-tools-server
Description:
server for Emacs's pdf-tools
This package contain the server needed by elpa-pdf-tools to transform pdf into png to be displayed by Emacs. . You probably need it only for elpa-pdf-tools
Homepage: https://github.com/politza/pdf-tools
Version: 0.80-1build1
Section: universe/text