hershey-font-gnuplot: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/hershey-font-gnuplot - from package: hershey-font-gnuplot

You may install the required package with command apt-get install {package}
Error in other languages:
hershey-font-gnuplot: bevel nie gevind nie
hershey-font-gnuplot: comandă negăsită
hershey-font-gnuplot: comando não encontrado
hershey-font-gnuplot: commande introuvable
hershey-font-gnuplot: command not found
hershey-font-gnuplot: käsku ei ole
hershey-font-gnuplot: không tìm thấy lệnh
hershey-font-gnuplot: komanda nerasta
hershey-font-gnuplot: Kommando nicht gefunden.
hershey-font-gnuplot: kommandot finns inte
hershey-font-gnuplot: komut yok
hershey-font-gnuplot: nie znaleziono polecenia
hershey-font-gnuplot: níor aimsíodh an t-ordú
hershey-font-gnuplot: no se encontró la orden
hershey-font-gnuplot: no s'ha trobat l'ordre
hershey-font-gnuplot: opdracht niet gevonden
hershey-font-gnuplot: parancs nem található
hershey-font-gnuplot: perintah tidak ditemukan
hershey-font-gnuplot: príkaz nenájdený
hershey-font-gnuplot: příkaz nenalezen
hershey-font-gnuplot: команда не найдена
hershey-font-gnuplot: командата не е открита
hershey-font-gnuplot: 命令找不到
hershey-font-gnuplot: コマンドが見つかりません