Language

perl: warning: Falling back to a fallback locale (“C.UTF-8”).

sudo apt-get install locales-all

dpkg-reconfigure locales

On a Linux server, if the language is different, you can change it to English for the current session by running

export LC_ALL=C

Example

root@root1229:~# ll
-bash: ll: Kommando nicht gefunden.
root@root1229:~# export LC_ALL=C
root@root1229:~# ll
-bash: ll: command not found
root@root1229:~# 

See current language

root@hestia-lnx:~# locale
LANG=fr_FR.UTF-8
LANGUAGE=
LC_CTYPE="fr_FR.UTF-8"
LC_NUMERIC="fr_FR.UTF-8"
LC_TIME="fr_FR.UTF-8"
LC_COLLATE="fr_FR.UTF-8"
LC_MONETARY="fr_FR.UTF-8"
LC_MESSAGES="fr_FR.UTF-8"
LC_PAPER="fr_FR.UTF-8"
LC_NAME="fr_FR.UTF-8"
LC_ADDRESS="fr_FR.UTF-8"
LC_TELEPHONE="fr_FR.UTF-8"
LC_MEASUREMENT="fr_FR.UTF-8"
LC_IDENTIFICATION="fr_FR.UTF-8"
LC_ALL=
root@hestia-lnx:~# 

List Available Languages

root@hestia-lnx:~# localectl list-locales
C.UTF-8
en_US.utf8
fr_FR.utf8
root@hestia-lnx:~#

Change langauage

localectl set-locale LANG=en_US.UTF-8

locale-gen