uzbl-tabbed: 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-tabbed - from package: uzbl

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

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