resgen: 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 CentOS possible default full paths are:

/usr/bin/resgen - from package: mono-devel

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/resgen - from package: mono-devel

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

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