H14 error in heroku - "no web processes running"

Procfile: mind the caps and format

Review your Procfile for possible errors. The file name should start with an upper-case 'P' and be in the correct format:

<process type>: <command>

<!--They say Java and Python are similar. Try telling that to your Procfile. Be specific with your command -->

Keep your unicorn in the virtual petting zoo

For applications running Python, endeavor that gunicorn is installed within the Heroku app's virtual environment. To include this, find requirements.txt or the Pipfile.

<!-- Yes, unicorns exist in the programming world too!-->

Empty commits as a redeployment tool

Make an empty commit and redeploy to trigger an application restart:

git commit --allow-empty -m "Empty commit. Why? Because I can"
git push heroku master

<!--Who needs a reason for restart? Not us-->

Monitor changes closely

Recent modifications to your Heroku account might have affected dyno usage. Double-check your plan's dyno availability.

<!--Twist and turns aren't just for plots-->

Decipher the logs

Examine your Heroku logs to get better insights. Just run this:

heroku logs --tail

Keep an eye out for errors during app start-up. Those are your sherlock clues to the underlying problems.

<!--Remember, Watson: When in doubt, log it out-->

Ensure your dependencies get along

To avoid start-up failures, ensure that your Flask, passlib, SQLAlchemy, Werkzeug, gunicorn, and gevent versions do not clash.

<!--Version misalignment: More dramatic than soaps-->

Mastering buildpacks

It may become necessary to reset your buildpacks by running the following commands:

heroku buildpacks:clear
heroku buildpacks:add heroku/python

<!--Building with packs is as much fun when stuffed inside Python-->

Doing so ensures the precise setup of your environment for subsequent deployments.