As point it out in several comments , fixing the missing GPG solved the problem for me . In my case was the new skype version :
# make sure you have 'apt-transport-https' installed dpkg -s apt-transport-https > /dev/null || bash -c "sudo apt-get update; sudo apt-get install apt-transport-https -y" curl https://repo.skype.com/data/SKYPE-GPG-KEY | sudo apt-key add - echo "deb [arch=amd64] https://repo.skype.com/deb stable main" | sudo tee /etc/apt/sources.list.d/skype-stable.list sudo apt-get update sudo apt-get install skypeforlinux -y
As point it out in several comments , fixing the missing GPG solved the problem for me .
In my case was the new skype version :
# make sure you have 'apt-transport- https' installed /repo.skype. com/data/ SKYPE-GPG- KEY | sudo apt-key add - /repo.skype. com/deb stable main" | sudo tee /etc/apt/ sources. list.d/ skype-stable. list
dpkg -s apt-transport-https > /dev/null || bash -c "sudo apt-get update; sudo apt-get install apt-transport-https -y"
curl https:/
echo "deb [arch=amd64] https:/
sudo apt-get update
sudo apt-get install skypeforlinux -y