flask.cli.NoAppException: Failed to find application in module "application". Are you sure it contains a Flask application? Maybe you wrapped it in a WSGI middleware or you are using a factory function.
Maybe you've done something to the lines dealing with
app = Flask(__name__) at the top of your
application.py, or messed up one of your imports.
You can go
Show File Revision History to compare different versions of your file.
In case of a failed import, you might get some meaningful error message if you call
python application.py directly.