font-manager: 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/font-manager - from package: font-manager

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

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