uhd_images_downloader: 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/uhd_images_downloader - from package: uhd-host

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