gtrayicon: 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/gtrayicon - from package: gtrayicon

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

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