xyconv: 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 Debian possible default full paths are:

/usr/bin/xyconv - from package: libxy-bin

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

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