desktopnova-tray: command not found

Have You tried accessing the binary with the full path?

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/desktopnova-tray - from package: desktopnova-tray

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