getting error when doing the composer install

Drupal version was 8.6.2 and moved to new server. When doing the core update , getting an error like below.

 Problem 1 - remove drupal/drupal No version set (parsed as 1.0.0)|remove drupal/core 8.6.3 - don't install drupal/core 8.6.2|remove drupal/drupal No version set (parsed as 1.0.0) - don't install drupal/core 8.6.3|remove drupal/drupal No version set (parsed as 1.0.0) - don't install drupal/core 8.6.x-dev|remove drupal/drupal No version set (parsed as 1.0.0) - don't install drupal/core 8.7.x-dev|remove drupal/drupal No version set (parsed as 1.0.0) - don't install drupal/core 8.6.3|remove drupal/drupal No version set (parsed as 1.0.0) - Installation request for drupal/drupal No version set (parsed as 1.0.0) -> satisfiable by drupal/drupal[No version set (parsed as 1.0.0)]. - Installation request for drupal/core ^8.6.2 -> satisfiable by drupal/core[8.6.2, 8.6.3, 8.6.x-dev, 8.7.x-dev] 

i have tried the composer install by removing composer.lock, vendor and core. Still getting same error.

Updated with my composer.json

{ "name": "drupal/drupal", "description": "Drupal is an open source content management platform powering millions of websites and applications.", "type": "project", "license": "GPL-2.0+", "require": {     "composer/installers": "^1.0.24",     "wikimedia/composer-merge-plugin": "^1.4",     "drupal/core": "^8.6.2",     "drush/drush": "^9.2",     "drupal/s3fs": "^3.0",     "drupal/csv_serialization": "^1.4" }, "minimum-stability": "dev", "prefer-stable": true, "config": {     "preferred-install": "dist",     "autoloader-suffix": "Drupal8" }, "extra": {     "_readme": [         "By default Drupal loads the autoloader from ./vendor/autoload.php.",         "To change the autoloader you can edit ./autoload.php.",         "This file specifies the packages.drupal.org repository.",         "You can read more about this composer repository at:",         "https://www.drupal.org/node/2718229"     ],     "merge-plugin": {         "include": [             "core/composer.json"         ],         "recurse": false,         "replace": false,         "merge-extra": false     },     "installer-paths": {         "core": ["type:drupal-core"],         "modules/contrib/{$  name}": ["type:drupal-module"],         "profiles/contrib/{$  name}": ["type:drupal-profile"],         "themes/contrib/{$  name}": ["type:drupal-theme"],         "drush/contrib/{$  name}": ["type:drupal-drush"],         "modules/custom/{$  name}": ["type:drupal-custom-module"],         "themes/custom/{$  name}": ["type:drupal-custom-theme"]     } }, "autoload": {     "psr-4": {         "Drupal\Core\Composer\": "core/lib/Drupal/Core/Composer"     } }, "scripts": {     "pre-autoload-dump": "Drupal\Core\Composer\Composer::preAutoloadDump",     "post-autoload-dump": [       "Drupal\Core\Composer\Composer::ensureHtaccess"     ],     "post-package-install": "Drupal\Core\Composer\Composer::vendorTestCodeCleanup",     "post-package-update": "Drupal\Core\Composer\Composer::vendorTestCodeCleanup" }, "repositories": [     {         "type": "composer",         "url": "https://packages.drupal.org/8"     } ] 

}