flappclient: 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/flappclient - from package: python-foolscap

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

On Debian possible default full paths are:

/usr/bin/flappclient - from package: python-foolscap

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

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