[FIXED] How to downgrade Laravel version 5.8 to 5.1 in Ubuntu server?

Issue

"name": "laravel/laravel",
 "description": "The Laravel Framework.",
 "keywords": [
     "framework",
     "laravel"
 ],
 "license": "MIT",
 "type": "project",
 "require": {
     "php": ">=5.5.9",
     "laravel/framework": "^5.8.0",

Solution

Simply update the composer.json so that it looks like this "require":"{..., "laravel/framework":"5.1.*" then run composer update.
You may want to downgrade some other dependencies too, if the command fails (it will show you where the problem is, though).

Note: It is NOT recommended to run composer update on production server. You may want to do it on your local machine, and after pushing the code to production, run composer install there.

Answered By - Qumber