bareos-tray-monitor: 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/bareos-tray-monitor - from package: bareos-traymonitor

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

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