tapconvert: 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 CentOS possible default full paths are:

/usr/bin/tapconvert - from package: python-twisted-core

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/tapconvert - from package: python-twisted-core

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

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