Note that the development build is not optimized. To create a production build, use npm run build.

[dvajs]

Note that the development build is not optimized. To create a production build, use npm run build.

[sorrycc]

Have you enabled a proxy?

[tahiriabdo131]

you are forget to export an component

[abdalshafiealmajdoup]

install nvm ,
node -v, please select node stable v16.16.0,
nvm install v16.16.0,
nvm now use v16.16.0,
sudo rm -r package-lock.json,
sudo rm -r node_modules,
sudo rm -r dist,
npm install --save,
npm run build,
npm run serve -- --port 8080
...... Done......

[Navdeep-bains]

after create your react-app and before start your server you have to run this command npm run build after this command start you server i hope this will be great for you

[coderbekhub]

after create your react-app and before start your server you have to run this command npm run build after this command start you server i hope this will be great for you
i did npm run build and i get error in terminal saying failed compiled help me

[blockofcodes]

Change the URL to http://localhost:3000/ << this is the default set URL when you install react

[princecharming519]

How can I enable proxy?

[ShivaShankerReddy]

@sorrycc i enabled proxy and go that note inside terminal.

[avijadu]

after create your react-app and before start your server you have to run this command npm run build after this command start you server i hope this will be great for you

I tried it but their is no solution. I also use localhost:3000

[UtmostCreator]

you are forget to export an component

Yeah, I have exactly this problem. in babel.config.js file, but in your case it could be any other file.
Before:

// ./babel.config.js
module.exports = {
  presets: ["@vue/cli-plugin-babel/preset"],
};

After:

// ./babel.config.js
export default module.exports = {
  presets: ["@vue/cli-plugin-babel/preset"],
};

However, if I resetar the client, then I have the following error:

 ERROR  SyntaxError: DISK:\path\to\my\project\client\babel.config.js: Error while loading config - Unexpected token 'export'
DISK:\path\to\my\project\client\babel.config.js:1
export default module.exports = {
^^^^^^