test_permission_assertions: 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/lib/python2.6/site-packages/askbot/bin/test_permission_assertions - from package: askbot

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

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