obex_send: 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/lib/plainbox-providers-1/checkbox/bin/obex_send - from package: plainbox-provider-checkbox

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