last-dotplot: 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/last-dotplot - from package: last-align

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

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