multicat: 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/multicat - from package: multicat

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