condor_credd: 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/sbin/condor_credd - from package: htcondor

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

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