clc-unregister-user-package: 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/clc-unregister-user-package - from package: common-lisp-controller

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

On Debian possible default full paths are:

/usr/bin/clc-unregister-user-package - from package: common-lisp-controller

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

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