upssched-cmd: 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/bin/upssched-cmd - from package: nut-client

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

On Debian possible default full paths are:

/bin/upssched-cmd - from package: nut-client

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

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