uzbl: 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/uzbl - from package: uzbl

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

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