ginsi: 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 Debian possible default full paths are:

/usr/lib/mafft/bin/ginsi - from package: mafft

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