wmsystemtray: 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/wmsystemtray - from package: wmsystemtray

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

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