kdtquery: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

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/kdtquery - from package: gerris-mpi
/usr/bin/kdtquery - from package: gerris

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