nxsummary: 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/nxsummary - from package: nexus-tools

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

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