chkconc: 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/chkconc - from package: Canna

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

On Debian possible default full paths are:

/usr/bin/chkconc - from package: canna-utils

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

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