uwsgi_python34: 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/uwsgi_python34 - from package: uwsgi-plugin-python3

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

Error in other languages:
uwsgi_python34: bevel nie gevind nie
uwsgi_python34: comandă negăsită
uwsgi_python34: comando não encontrado
uwsgi_python34: commande introuvable
uwsgi_python34: command not found
uwsgi_python34: käsku ei ole
uwsgi_python34: không tìm thấy lệnh
uwsgi_python34: komanda nerasta
uwsgi_python34: Kommando nicht gefunden.
uwsgi_python34: kommandot finns inte
uwsgi_python34: komut yok
uwsgi_python34: nie znaleziono polecenia
uwsgi_python34: níor aimsíodh an t-ordú
uwsgi_python34: no se encontró la orden
uwsgi_python34: no s'ha trobat l'ordre
uwsgi_python34: opdracht niet gevonden
uwsgi_python34: parancs nem található
uwsgi_python34: perintah tidak ditemukan
uwsgi_python34: príkaz nenájdený
uwsgi_python34: příkaz nenalezen
uwsgi_python34: команда не найдена
uwsgi_python34: командата не е открита
uwsgi_python34: 命令找不到
uwsgi_python34: コマンドが見つかりません