split_combined_hex: 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/sbin/split_combined_hex - from package: hostap-utils

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

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