validateDescriptor: 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/validateDescriptor - from package: uima-utils

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

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