The errors are saying that the X11 graphics driver does not know what font to use (see this discussion). By default, R installs with the C locale set. For linux, you need to set a UTF-8 locale which is prefixed by the language.
For example, for the English in the US, you would set it to 'en_US.UTF-8'.
Try setting the system locale with the Sys.setlocale
command like so:
Sys.setlocale("LC_CTYPE", "en_US.UTF-8")
Sys.setlocale("LC_ALL", "en_US.UTF-8")
This can be done through the .bashrc
configuration file like so:
export LC_CTYPE=en_US.UTF-8
export LC_ALL=en_US.UTF-8
(source)