npm run watch doesn't works after upgrade

@Nakov Thankyou but not worked for me

@ottaviane As pointed out by @nakov you dont have mix installed https://laravel-mix.com/docs/6.0/installation

@Sinnbeck Thank you very mutch. So I made all, I installe laravel-mix but when I do :'npx mix' I obtain

npx mix
[webpack-cli] Error: Cannot find module 'vue/compiler-sfc'
Require stack:
- /home/ottaviane/Sviluppo/SquadrarioWeb/node_modules/vue-loader/dist/index.js
- /home/ottaviane/Sviluppo/SquadrarioWeb/node_modules/laravel-mix/src/components/Vue.js
- /home/ottaviane/Sviluppo/SquadrarioWeb/node_modules/laravel-mix/src/components/ComponentRegistrar.js
- /home/ottaviane/Sviluppo/SquadrarioWeb/node_modules/laravel-mix/src/Mix.js
- /home/ottaviane/Sviluppo/SquadrarioWeb/node_modules/laravel-mix/setup/webpack.config.js
- /home/ottaviane/Sviluppo/SquadrarioWeb/node_modules/webpack-cli/lib/webpack-cli.js
- /home/ottaviane/Sviluppo/SquadrarioWeb/node_modules/webpack-cli/lib/bootstrap.js
- /home/ottaviane/Sviluppo/SquadrarioWeb/node_modules/webpack-cli/bin/cli.js
- /home/ottaviane/Sviluppo/SquadrarioWeb/node_modules/webpack/bin/webpack.js
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:815:15)
    at Function.Module._load (internal/modules/cjs/loader.js:667:27)
    at Module.require (internal/modules/cjs/loader.js:887:19)
    at require (internal/modules/cjs/helpers.js:74:18)
    at Object.<anonymous> (/home/ottaviane/Sviluppo/SquadrarioWeb/node_modules/vue-loader/dist/index.js:8:24)
    at Module._compile (internal/modules/cjs/loader.js:999:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1027:10)
    at Module.load (internal/modules/cjs/loader.js:863:32)
    at Function.Module._load (internal/modules/cjs/loader.js:708:14)
    at Module.require (internal/modules/cjs/loader.js:887:19) {
  code: 'MODULE_NOT_FOUND',
  requireStack: [
    '/home/ottaviane/Sviluppo/SquadrarioWeb/node_modules/vue-loader/dist/index.js',
    '/home/ottaviane/Sviluppo/SquadrarioWeb/node_modules/laravel-mix/src/components/Vue.js',
    '/home/ottaviane/Sviluppo/SquadrarioWeb/node_modules/laravel-mix/src/components/ComponentRegistrar.js',
    '/home/ottaviane/Sviluppo/SquadrarioWeb/node_modules/laravel-mix/src/Mix.js',
    '/home/ottaviane/Sviluppo/SquadrarioWeb/node_modules/laravel-mix/setup/webpack.config.js',
    '/home/ottaviane/Sviluppo/SquadrarioWeb/node_modules/webpack-cli/lib/webpack-cli.js',
    '/home/ottaviane/Sviluppo/SquadrarioWeb/node_modules/webpack-cli/lib/bootstrap.js',
    '/home/ottaviane/Sviluppo/SquadrarioWeb/node_modules/webpack-cli/bin/cli.js',
    '/home/ottaviane/Sviluppo/SquadrarioWeb/node_modules/webpack/bin/webpack.js'
  ]
}

And I tryed also 'npm i @vue/compiler-sfc' but it doesn't work

@ottaviane Maybe undo your changes with git, and see how the package.json was before you started upgrading?

@Sinnbeck Ok but how you do it?

@ottaviane Do you use git?

@Sinnbeck I think not!

@ottaviane Ok. Do you have a backup of the file on your production server? Or another computer?

@Sinnbeck Yes, a backup of this night What I have to do?

@ottaviane Can you post the contents of that file? I assume it was working back then?

@Sinnbeck ok. what files? The entire project? or only some files? can you specify please? thank you very mutch

@ottaviane package.json

@Sinnbeck ok. Excuse me. This is my old package.json that worked for me yesterday:

{
    "private": true,
    "scripts": {
        "development": "mix",
        "watch": "mix watch",
        "watch-poll": "mix watch -- --watch-options-poll=1000",
        "hot": "mix watch --hot",
        "prod": "mix --production",
        "production": "mix --production"
    },
    "devDependencies": {
        "axios": "^0.21.1",
        "bootstrap": "^4.6.0",
        "browser-sync": "^2.26.14",
        "browser-sync-webpack-plugin": "^2.3.0",
        "cross-env": "^7.0",
        "jquery": "^3.6.0",
        "jquery-scroll-lock": "^3.1.3",
        "jquery.appear": "^1.0.1",
        "js-cookie": "^2.2.1",
        "laravel-mix": "^6.0.18",
        "lodash": "^4.17.19",
        "popper.js": "^1.16.1",
        "postcss": "^8.2.12",
        "resolve-url-loader": "^3.1.2",
        "sass": "^1.32.8",
        "sass-loader": "^8.0.2",
        "simplebar": "^5.3.0",
        "vue": "^2.6.12",
        "vue-loader": "^15.9.6",
        "vue-template-compiler": "^2.6.12"
    },
    "dependencies": {
        "codemirror": "^5.60.0",
        "dedent": "^0.7.0",
        "html-to-image": "^1.9.0",
        "tiptap": "^1.32.2",
        "tiptap-extensions": "^1.35.2",
        "vue-codemirror": "^4.0.6",
        "vue-loading-button": "^0.2.0",
        "vuex": "^3.6.2"
    }
}