fixnt: 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/fixnt - from package: a2ps

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

On Debian possible default full paths are:

/usr/bin/fixnt - from package: a2ps

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

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