xless: 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/xless - from package: xless

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

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