Upgrading to 8.4 [Part Deux]

I am relatively new to Composer. I just upgraded from 8.3.7 to 8.4.0 after reading every entry on upgrading in this forum. My site now is totally down. I have had to restore from a backup. Here are the steps that I followed. Can someone point out what the problem might be?

The steps that I followed:

1) Renamed composer.lock, core and vendor to _composer.lock, _core and _vender, respectively.

2) Added “drupal/core”: “~8.4” to my composer.json. (see below for my composer.json file).

3) $composer update –with-dependencies

My error messages:

-bash-4.1$ composer update drupal/core –with-dependencies

Loading composer repositories with package information

Updating dependencies (including require-dev)

Package operations: 37 installs, 0 updates, 0 removals

  – Installing composer/installers (v1.4.0): Loading from cache

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing wikimedia/composer-merge-plugin (v1.4.1): Loading from cache

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing webmozart/assert (1.2.0): Loading from cache

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing webmozart/path-util (2.3.0): Loading from cache

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing webflo/drupal-finder (1.0.0): Loading from cache

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing symfony/yaml (v3.3.10): Downloading (100%)         

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing symfony/polyfill-mbstring (v1.6.0): Downloading (100%)         

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing symfony/var-dumper (v3.3.10): Downloading (100%)         

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing symfony/process (v3.3.10): Downloading (100%)         

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing symfony/finder (v3.3.10): Downloading (100%)         

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing symfony/event-dispatcher (v3.3.10): Downloading (100%)         

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing psr/log (1.0.2): Loading from cache

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing symfony/debug (v3.3.10): Downloading (100%)         

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing symfony/console (v3.3.10): Downloading (100%)         

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing symfony/filesystem (v3.3.10): Downloading (100%)         

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing symfony/config (v3.3.10): Downloading (100%)         

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing sebastian/version (1.0.6): Loading from cache

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing jakub-onderka/php-console-color (0.1): Loading from cache

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing jakub-onderka/php-console-highlighter (v0.3.2): Loading from cache

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing dnoegel/php-xdg-base-dir (0.1): Loading from cache

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing nikic/php-parser (v3.1.1): Downloading (100%)         

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing psy/psysh (v0.8.13): Downloading (100%)         

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing phpdocumentor/reflection-docblock (2.0.5): Loading from cache

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing pear/console_table (v1.3.0): Loading from cache

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing psr/container (1.0.0): Loading from cache

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing container-interop/container-interop (1.2.0): Loading from cache

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing league/container (2.4.1): Loading from cache

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing dflydev/dot-access-data (v1.1.0): Loading from cache

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing grasmash/yaml-expander (1.2.0): Downloading (100%)         

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing consolidation/output-formatters (3.1.12): Downloading (100%)         

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing consolidation/log (1.0.3): Loading from cache

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing consolidation/annotated-command (2.8.1): Downloading (100%)         

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing consolidation/config (1.0.6): Downloading (100%)         

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing consolidation/robo (1.1.4): Downloading (100%)         

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing twig/twig (v1.35.0): Downloading (100%)         

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing chi-teck/drupal-code-generator (1.20.0): Downloading (100%)         

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

  – Installing drush/drush (9.0.0-beta7): Downloading (100%)         

Class DrupalCoreComposerComposer is not autoloadable, can not call post-package-install script

symfony/var-dumper suggests installing ext-symfony_debug ()

symfony/event-dispatcher suggests installing symfony/dependency-injection ()

symfony/event-dispatcher suggests installing symfony/http-kernel ()

psy/psysh suggests installing ext-pdo-sqlite (The doc command requires SQLite to work.)

psy/psysh suggests installing hoa/console (A pure PHP readline implementation. You’ll want this if your PHP install doesn’t already support readline or libedit.)

phpdocumentor/reflection-docblock suggests installing dflydev/markdown (~1.0)

phpdocumentor/reflection-docblock suggests installing erusev/parsedown (~1.0)

pear/console_table suggests installing pear/Console_Color2 (>=0.1.2)

consolidation/robo suggests installing pear/archive_tar (Allows tar archives to be created and extracted in taskPack and taskExtract, respectively.)

consolidation/robo suggests installing henrikbjorn/lurker (For monitoring filesystem changes in taskWatch)

consolidation/robo suggests installing patchwork/jsqueeze (For minifying JS files in taskMinify)

consolidation/robo suggests installing natxet/CssMin (For minifying CSS files in taskMinify)

Writing lock file

Generating autoload files

Class DrupalCoreComposerComposer is not autoloadable, can not call pre-autoload-dump script

Class DrupalCoreComposerComposer is not autoloadable, can not call post-autoload-dump script

Loading composer repositories with package information

Updating dependencies (including require-dev)

Nothing to install or update

Generating autoload files

Class DrupalCoreComposerComposer is not autoloadable, can not call pre-autoload-dump script

Class DrupalCoreComposerComposer is not autoloadable, can not call post-autoload-dump script

My composer.json file:

{
    "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",
        "drush/drush": "9.*",
        "drupal/core": "~8.4"
    },
    "replace": {
        "drupal/core": "~8.3"
    },
    "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": {
            "DrupalCoreComposer": "core/lib/Drupal/Core/Composer"
        }
    },
    "scripts": {
        "pre-autoload-dump": "DrupalCoreComposerComposer::preAutoloadDump",
        "post-autoload-dump": [
            "DrupalCoreComposerComposer::ensureHtaccess"
        ],
        "post-package-install": "DrupalCoreComposerComposer::vendorTestCodeCleanup",
        "post-package-update": "DrupalCoreComposerComposer::vendorTestCodeCleanup"
    },
    "repositories": {
        "0": {
            "type": "composer",
            "url": "https://packages.drupal.org/8"
        },
        "drupal": {
            "type": "composer",
            "url": "https://packages.drupal.org/8"
        }
    }
}
Drupal version: 


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