quality_scores_plot.py: 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/lib/qiime/bin/quality_scores_plot.py - from package: qiime

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

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