ui-auto-update: 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/ui-auto-update - from package: ui-auto

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

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