netplex-admin: 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/netplex-admin - from package: libocamlnet-ocaml-bin

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

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