live555ProxyServer: 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/live555ProxyServer - from package: livemedia-utils

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

Error in other languages:
live555ProxyServer: bevel nie gevind nie
live555ProxyServer: comandă negăsită
live555ProxyServer: comando não encontrado
live555ProxyServer: commande introuvable
live555ProxyServer: command not found
live555ProxyServer: käsku ei ole
live555ProxyServer: không tìm thấy lệnh
live555ProxyServer: komanda nerasta
live555ProxyServer: Kommando nicht gefunden.
live555ProxyServer: kommandot finns inte
live555ProxyServer: komut yok
live555ProxyServer: nie znaleziono polecenia
live555ProxyServer: níor aimsíodh an t-ordú
live555ProxyServer: no se encontró la orden
live555ProxyServer: no s'ha trobat l'ordre
live555ProxyServer: opdracht niet gevonden
live555ProxyServer: parancs nem található
live555ProxyServer: perintah tidak ditemukan
live555ProxyServer: príkaz nenájdený
live555ProxyServer: příkaz nenalezen
live555ProxyServer: команда не найдена
live555ProxyServer: командата не е открита
live555ProxyServer: 命令找不到
live555ProxyServer: コマンドが見つかりません