nxcmd: 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/nxcmd - from package: libnxcl-bin

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

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