compseq: 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/bin/compseq - from package: emboss

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