unicode_start: 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 CentOS possible default full paths are:

/bin/unicode_start - from package: kbd

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/bin/unicode_start - from package: kbd

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

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