Screen requires a tty to start. Crontab jobss don't get a tty.

Running uwsgi inside screen is probably unnecessary.

If you can, instead of running this inside screen inside a cron job, it would be better to start it as a systemd service. At a glance, these instructions look like they might be helpful https://uwsgi-docs.readthedocs.io/en/latest/Systemd.html

If setting this up as a systemd service is not an option, there are several other ways to allow a background job to save its output to a log file.

Screen requires a tty to start. Crontab jobs don't get a tty.

Running uwsgi inside screen is probably unnecessary.

If you can, instead of running this inside screen inside a cron job, it would be better to start it as a systemd service. At a glance, these instructions look like they might be helpful https://uwsgi-docs.readthedocs.io/en/latest/Systemd.html

If setting this up as a systemd service is not an option, there are several other ways to allow a background job to save its output to a log file.