[Vuejs]-Laravel Composer Error: Installation failed, reverting ./composer.json to its original content

Your problem is with your laravel version, which is old for latest laravel/ui Project.

Try with a fresh project:

composer create-project --prefer-dist laravel/laravel blog For new project, replace your project name with blog, then try composer require laravel/ui to add vue/react/angular scaffolds.

Also I’m suggesting to do a new project since you said you’re new to laravel and you should keep your project and libraries up to date.

Full Laravel Installation Documents Here

Edit:

If you don’t want to create a new project you can simply, edit your composer.json in project and change these lines to the latest versions or just replace parts with below:

"require": {
    "php": "^7.2.5",
    "fideloper/proxy": "^4.2",
    "laravel/framework": "^7.24",
    "laravel/tinker": "^2.0",
 }

Then simply run Composer update, ofc there are some big changes to take care since you’re using 5.* but this is where you should start to just simply include new ui library to project.

Good Luck

Your problem is explained by the following two lines:

- laravel/ui 2.x-dev requires illuminate/support ^7.0|^8.0 -> satisfiable by illuminate/support[7.x-dev, 8.x-dev, v7.0.0, v7.0.1, v7.0.2, v7.0.3, v7.0.4, v7.0.5, v7.0.6, v7.0.7, v7.0.8, v7.1.0, v7.1.1, v7.1.2, v7.1.3, v7.10.0, v7.10.1, v7.10.2, v7.10.3, v7.11.0, v7.12.0, v7.13.0, v7.14.0, v7.14.1, v7.15.0, v7.16.0, v7.16.1, v7.17.0, v7.17.1, v7.17.2, v7.18.0, v7.19.0, v7.19.1, v7.2.0, v7.2.1, v7.2.2, v7.20.0, v7.21.0, v7.22.0, v7.22.1, v7.22.2, v7.22.3, v7.22.4, v7.23.0, v7.23.1, v7.23.2, v7.24.0, v7.25.0, v7.26.0, v7.26.1, v7.27.0, v7.3.0, v7.4.0, v7.5.0, v7.5.1, v7.5.2, v7.6.0, v7.6.1, v7.6.2, v7.7.0, v7.7.1, v7.8.0, v7.8.1, v7.9.0, v7.9.1, v7.9.2].
- laravel/ui v2.2.0 requires illuminate/support ^7.0|^8.0 -> satisfiable by illuminate/support[7.x-dev, 8.x-dev, v7.0.0, v7.0.1, v7.0.2, v7.0.3, v7.0.4, v7.0.5, v7.0.6, v7.0.7, v7.0.8, v7.1.0, v7.1.1, v7.1.2, v7.1.3, v7.10.0, v7.10.1, v7.10.2, v7.10.3, v7.11.0, v7.12.0, v7.13.0, v7.14.0, v7.14.1, v7.15.0, v7.16.0, v7.16.1, v7.17.0, v7.17.1, v7.17.2, v7.18.0, v7.19.0, v7.19.1, v7.2.0, v7.2.1, v7.2.2, v7.20.0, v7.21.0, v7.22.0, v7.22.1, v7.22.2, v7.22.3, v7.22.4, v7.23.0, v7.23.1, v7.23.2, v7.24.0, v7.25.0, v7.26.0, v7.26.1, v7.27.0, v7.3.0, v7.4.0, v7.5.0, v7.5.1, v7.5.2, v7.6.0, v7.6.1, v7.6.2, v7.7.0, v7.7.1, v7.8.0, v7.8.1, v7.9.0, v7.9.1, v7.9.2].

To install laravel/ui 2.x, you need to have illuminate/support 7.x or 8.x, which corresponds to laravel/framework 7.x or 8.x.

To make it work with your version of laravel (5.8), you need to find a version of that library that does work with that version of laravel. If you go to packagist, you can browse all versions of laravel/ui, and it turns out that 1.2.0 does support laravel 5.8. You can thus solve your problem by installing an earlier version composer require laravel/ui:1.2.0. Note that this version might or might not contain the functionality you seek though. If you have the option of upgrading laravel instead, that is probably the better option.

You installed laravel/ui version 3.0 which corresponds laravel 8.x.
you should install ui 2.x version with this command:

composer require laravel/ui:2.x

If you are using Laravel 6 run the commands:

composer require laravel/ui "2.x"

php artisan ui vue --auth

npm install && npm run dev