bt_filter: 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:

/usr/bin/bt_filter - from package: retrace-server

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

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