watchreader: 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:

/opt/opennx/bin/watchreader - from package: opennx

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

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