React app runs locally, crashes when on Heroku error code=H10
Just npm i serve to install serve then or you could use yarn instead of npm
You can change your scripts in package.json file, it seemed to be caused by update by react.
"scripts": {"dev": "react-scripts start","start": "serve -s build","build": "react-scripts build","heroku-postbuild": "npm run build"}Hope it fixes your problem.
I face the same problem, it has worked for me.
add "serve" to application.
example:npm add serve or yarn add serve
after change scripts in package.json
"scripts": { "dev": "react-scripts start", "start": "serve -s build", "build": "react-scripts build", "heroku-postbuild": "npm run build"}