try-from: 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/sbin/try-from - from package: tcp_wrappers

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

On Debian possible default full paths are:

/usr/sbin/try-from - from package: tcpd

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

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