uzbl-event-manager: command not found

Have You tried accessing the binary with the full path?

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-event-manager - from package: uzbl

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