rstartd: 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/rstartd - from package: x11-session-utils

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

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