unknown heroku error

i am experiencing following error while trying to run application on heroku

2011-06-03T11:24:25-07:00 heroku[nginx]: GET / HTTP/1.1
2011-06-03T18:24:37+00:00 her开发者_开发问答oku[router]: Error H14 (No web processes runnig)

that's the only message i am getting, and it's not even mentioned in heroku error codes at http://devcenter.heroku.com/articles/error-codes what could be the reason of this?

heroku restart

made it work properly again

As given on http://devcenter.heroku.com/articles/error-codes

H14 - No web processes running

This is most likely the result of scaling your web processes down to zero through the client.

$ heroku scale web=0

Use the heroku ps command to determine the state of your web processes.

If problems persists after heroku restart;
Destroy the heroku app and re-create.

Heroku restart

didn't fix the issue. I added a new line in my Gemfile (just a new line, no text) to force heroku to reinstall gems and this fixed the issue.