fmtree: 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/fmtree - from package: freebsd-buildutils

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

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