vnc2swf-play: 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 CentOS possible default full paths are:

/usr/bin/vnc2swf-play - from package: pyvnc2swf

You may install the required package with command yum install {package}
Error in other languages:
vnc2swf-play: bevel nie gevind nie
vnc2swf-play: comandă negăsită
vnc2swf-play: comando não encontrado
vnc2swf-play: commande introuvable
vnc2swf-play: command not found
vnc2swf-play: käsku ei ole
vnc2swf-play: không tìm thấy lệnh
vnc2swf-play: komanda nerasta
vnc2swf-play: Kommando nicht gefunden.
vnc2swf-play: kommandot finns inte
vnc2swf-play: komut yok
vnc2swf-play: nie znaleziono polecenia
vnc2swf-play: níor aimsíodh an t-ordú
vnc2swf-play: no se encontró la orden
vnc2swf-play: no s'ha trobat l'ordre
vnc2swf-play: opdracht niet gevonden
vnc2swf-play: parancs nem található
vnc2swf-play: perintah tidak ditemukan
vnc2swf-play: príkaz nenájdený
vnc2swf-play: příkaz nenalezen
vnc2swf-play: команда не найдена
vnc2swf-play: командата не е открита
vnc2swf-play: 命令找不到
vnc2swf-play: コマンドが見つかりません