I’m not getting any error message when running the app locally. I did a few tests and here’s what I found: It works after I add "static_path": os.path.join(os.getcwd(), "static") to the dict. After a few minutes, if I reload the app, it just load a blank page. If I comment "static_path": os.path.join(os.getcwd(), "static") and re-run the app locally, it works again.
UPDATE: It seems to working fine now locally (no idea why how it fixed itself though). However, I can’t manage to download the test file I put in the static folder after uploading the app on Heroku. I use https://appname.herokuapp.com:80/static/testfile and I get a ERR_SSL_PROTOCOL_ERROR error message after a few seconds.