Fatal error: Uncaught Error: Class "Illuminate\Database\Migrations\Migration" not found in C:\xampp\htdocs\database\migrations\2017_12_21_123452_add_custom_css_to_users_table.php:21 Stack trace: #0 {main} thrown in C:\xampp\htdocs\database\migrations\2017_12_21_123452_add_custom_css_to_users_table.php on line 21