webkit-image-gtk: 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/webkit-image-gtk - from package: webkit-image-gtk

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

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