Quickstart Flask application failing for some reason

Question

I created a fresh virtualenv environment for a Flask application called flask-test so that I could do some testing. Imagine my surprise when, runni

Answer 1

Seems like a bug: the related issue Werkzeug 0.11 with Flask 0.10.1 and 'app.debug = True' won't start. #798

I create a new virtual environment using python3.5 and meet the same error, but if I don't use the debug mode, it's fine.

And as the issue says, downgrade Werkzeug to 0.10.4 seem works. You can have a try.