Workflow deployment fails with "Failed to find a default file in the app artifacts folder (/). Valid default files: index.html,Index.html." error

Make sure you created an empty index.html error in the repository’s root. Static Web App deployments will fail if a startup file is not present in the repository's root.

Pull the changes from the repository, create an empty index.html file in the repository’s root, add, commit and push the changes back. A new deployment process will be started.