bltk_wl_reader_xse: 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/lib64/bltk/wl_reader/bin/bltk_wl_reader_xse - from package: bltk

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

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