man1x: command not found

Have You tried accessing the binary with the full path?

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/share/man/bin/man1x - from package: filesystem

You may install the required package with command yum install {package}
Error in other languages:
man1x: bevel nie gevind nie
man1x: comandă negăsită
man1x: comando não encontrado
man1x: commande introuvable
man1x: command not found
man1x: käsku ei ole
man1x: không tìm thấy lệnh
man1x: komanda nerasta
man1x: Kommando nicht gefunden.
man1x: kommandot finns inte
man1x: komut yok
man1x: nie znaleziono polecenia
man1x: níor aimsíodh an t-ordú
man1x: no se encontró la orden
man1x: no s'ha trobat l'ordre
man1x: opdracht niet gevonden
man1x: parancs nem található
man1x: perintah tidak ditemukan
man1x: príkaz nenájdený
man1x: příkaz nenalezen
man1x: команда не найдена
man1x: командата не е открита
man1x: 命令找不到
man1x: コマンドが見つかりません