classad_functional_tester: 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/classad_functional_tester - from package: classads-devel
/usr/bin/classad_functional_tester - from package: condor-classads-devel

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

On Debian possible default full paths are:

/usr/bin/classad_functional_tester - from package: htcondor

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

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