webcollage-helper: 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/webcollage-helper - from package: xscreensaver-screensaver-webcollage

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

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