Overview

If CircleCI is not able to build when a branch is created or updates are pushed to a pull request, first of all, please check the GitHub WebHook deliveries as this might help in discovering why a push to your repo has not resulted in a job on CircleCI.

Solution

If you are seeing the response 400 in spite of having the read/write/admin access to the repository, then this means that your secret generated by GH for the webhook is no longer present, or possible expired. To address this, first please try

1. Signing out of Github in your browser
2. Signing out of CircleCI
3. Then logging back into CircleCI via Github.

If that does not work, then the secret is no longer present. You can also follow the below steps to make CircleCI generate a new webhook, with a secret:

1. Unfollow the project from the CircleCI ‘Project settings’ page - click the ‘Unfollow’ button
2. Remove the webhook for the affected repo on GitHub (Settings > Webhooks and services)
3. Re-add the project by following the project again on the CircleCI ‘Project settings’ page

This should resolve your issue.

Additional Resources

• Generate New GitHub OAuth Webhook
• What to do if you suspect you have a secret leaked from CircleCI
• How to view your GitHub webhook deliveries
• How to view your GitLab Webhook Deliveries