crtmpserver: 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/sbin/crtmpserver - from package: crtmpserver

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

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