ktp-contactlist: 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/ktp-contactlist - from package: kde-telepathy-contact-list

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

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