uni2ascii: 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/uni2ascii - from package: uni2ascii

You may install the required package with command apt-get install {package}
Error in other languages:
uni2ascii: bevel nie gevind nie
uni2ascii: comandă negăsită
uni2ascii: comando não encontrado
uni2ascii: commande introuvable
uni2ascii: command not found
uni2ascii: käsku ei ole
uni2ascii: không tìm thấy lệnh
uni2ascii: komanda nerasta
uni2ascii: Kommando nicht gefunden.
uni2ascii: kommandot finns inte
uni2ascii: komut yok
uni2ascii: nie znaleziono polecenia
uni2ascii: níor aimsíodh an t-ordú
uni2ascii: no se encontró la orden
uni2ascii: no s'ha trobat l'ordre
uni2ascii: opdracht niet gevonden
uni2ascii: parancs nem található
uni2ascii: perintah tidak ditemukan
uni2ascii: príkaz nenájdený
uni2ascii: příkaz nenalezen
uni2ascii: команда не найдена
uni2ascii: командата не е открита
uni2ascii: 命令找不到
uni2ascii: コマンドが見つかりません