I am trying to install R
gpg --keyserver keyserver.ubuntu.com --recv-key E084DAB9
gpg: keyring `/home/milenko/.gnupg/secring.gpg' created
gpg: keyring `/home/milenko/.gnupg/pubring.gpg' created
gpg: requesting key E084DAB9 from hkp server keyserver.ubuntu.com
gpg: keyserver timed out
gpg: keyserver receive failed: keyserver error
This also does not help
gpg --keyserver keyserver.ubuntu.com:80 --recv-key E084DAB9
gpg: requesting key E084DAB9 from keyserver.ubuntu.com:80
gpgkeys: no keyserver host provided
gpg: keyserver internal error
gpg: keyserver receive failed: keyserver error
I am on Ubuntu 16.04.
Pretty old question, but hopes this helps someone: You need the protocol for the keyserver, e.g.