unifontksx: command not found

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/unifontksx - from package: unifont-bin

You may install the required package with command apt-get install {package}

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