update-profile-cache: 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/update-profile-cache - from package: desktop-profiles

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

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