Discussion on: Causes of Heroku H10-App Crashed Error And How To Solve Them

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Replies for: Thanks. It solved my problem on Heroku, but I can't run my app locally. After installing serve and modifying package.json, when I run npm start - ...

Uros Randelovic • Jul 19 '20 • Edited

Hi Haim,

If you run yarn start/npm start now it points to 'serve -s build' instead of 'react-scripts start'.

Make sure you've added below:

"dev": "react-scripts start",
"start": "serve -s build",

and to run your app locally do npm run dev not npm start

Haim Buchbut • Jul 19 '20

Thanks. It didn't work with "npm dev" (I got that "dev" is invalid command), but it did work with "npm run dev".

Lawrence Eagles • Jul 20 '20 • Edited

I am glad to hear this worked for you.
Just a side note:
commands like npm start can work directly because they are default commands from npm but custom commands like dev set by the user would only work with the run command. npm run dev. I hope this clears things up.