fastahardmask: 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/fastahardmask - from package: exonerate

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

On Debian possible default full paths are:

/usr/bin/fastahardmask - from package: exonerate

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

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