I built a Drupal 8.9 site with Composer on a DEV server and copied the files (& db) over to the LIVE server. 

The LIVE server did not have Composer installed previously so I installed it, locally.

The new website has its `composer.json` file from when I created the site and added modules.

I tried `composer update` to verify that composer will work when the time comes.

It fails and I don't know if I need to rip out the website and re-create it again (then copy select files back over).

---
---

When I run it I get the following output:

> Loading composer repositories with package information Updating dependencies Your requirements could not be resolved to an installable set of packages.
> 
> Problem 1
>     
>     - Conclusion: don't install drupal/core-recommended 8.9.x-dev (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.8.7 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.8.8 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.8.9 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.8.10 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.8.11 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.8.12 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.9.0 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.9.1 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.9.2 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.9.3 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.9.4 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.9.5 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.9.6 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.9.7 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.9.8 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.9.9 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.9.10 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.9.11 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.9.12 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.9.13 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.9.14 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.9.15 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.9.16 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.9.17 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.9.18 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.9.19 (conflict analysis result)
>     - Conclusion: don't install drupal/core-recommended 8.9.20 (conflict analysis result)
>     - drupal/core-recommended[8.8.0-beta1, ..., 8.9.0-rc1] require composer/installers v1.7.0 -> satisfiable by -> composer/installers[v1.7.0].
>     - composer/installers v1.7.0 requires composer-plugin-api ^1.0 -> found composer-plugin-api[2.1.0] but it does not match the constraint.
>     - symfony/polyfill-mbstring 1.23.x-dev is an alias of symfony/polyfill-mbstring dev-main and thus requires it to be installed too.
>     - easyrdf/easyrdf 0.9.1 requires ext-mbstring * -> satisfiable by symfony/polyfill-mbstring[dev-main, 1.23.x-dev (alias of dev-main)].
>     - You can only install one version of a package, so only one of these can be installed: symfony/polyfill-mbstring[dev-main, v1.0.0, ..., v1.23.1].
>     - drupal/core-recommended 8.8.x-dev requires easyrdf/easyrdf 0.9.1 -> satisfiable by easyrdf/easyrdf[0.9.1].
>     - drupal/core-recommended 8.8.x-dev requires symfony/polyfill-mbstring v1.12.0 -> satisfiable by symfony/polyfill-mbstring[v1.12.0].
>     - Root composer.json requires drupal/core-recommended ^8.8 -> satisfiable by drupal/core-recommended[8.8.0-beta1, ..., 8.9.x-dev].
> 
> To enable extensions, verify that they are enabled in your .ini files:
>
>     - /etc/php.ini
>     - /etc/php.ini
>     - /etc/php.d/20-bz2.ini
>     - /etc/php.d/20-calendar.ini
>     - /etc/php.d/20-ctype.ini
>     - /etc/php.d/20-curl.ini
>     - /etc/php.d/20-dom.ini
>     - /etc/php.d/20-exif.ini
>     - /etc/php.d/20-fileinfo.ini
>     - /etc/php.d/20-ftp.ini
>     - /etc/php.d/20-gd.ini
>     - /etc/php.d/20-gettext.ini
>     - /etc/php.d/20-iconv.ini
>     - /etc/php.d/20-json.ini
>     - /etc/php.d/20-mysqlnd.ini
>     - /etc/php.d/20-pdo.ini
>     - /etc/php.d/20-phar.ini
>     - /etc/php.d/20-simplexml.ini
>     - /etc/php.d/20-sockets.ini
>     - /etc/php.d/20-sqlite3.ini
>     - /etc/php.d/20-tokenizer.ini
>     - /etc/php.d/20-xml.ini
>     - /etc/php.d/20-xmlwriter.ini
>     - /etc/php.d/20-xsl.ini
>     - /etc/php.d/30-mcrypt.ini
>     - /etc/php.d/30-mysqli.ini
>     - /etc/php.d/30-pdo_mysql.ini
>     - /etc/php.d/30-pdo_sqlite.ini
>     - /etc/php.d/30-wddx.ini
>     - /etc/php.d/30-xmlreader.ini
>     - /etc/php.d/40-zip.ini 
>
> You can also run `php --ini` inside terminal to see which files are used by PHP in CLI mode.

---

Running `php --ini` comes up with a matching list

---

Contents of my `composer.json` file:

> $ clear && cat composer.json
>
>  {
>
> "name": "drupal/recommended-project",
>
> "description": "Project template for Drupal 8 projects with a relocated document root",
> 
> "type": "project",
> 
> "license": "GPL-2.0-or-later",
> 
> "homepage": "https://www.drupal.org/project/drupal",
> 
> "support": {
> 
> "docs": "https://www.drupal.org/docs/user_guide/en/index.html",
> 
> "chat": "https://www.drupal.org/node/314178"
> 
> },
> 
>    "repositories": [
>
>        {
>
>            "type": "composer",
>
>            "url": "https://packages.drupal.org/8"
>
>        }
>
>    ],
>
>    "require": {
>
>        "composer/installers": "^1.2",
>
>        "drupal/block_class": "^1.3",
>
>        "drupal/bootstrap": "^3.23",
>
>        "drupal/captcha": "^1.2",
>
>        "drupal/core-composer-scaffold": "^8.8",
>
>        "drupal/core-project-message": "^8.8",
>
>        "drupal/core-recommended": "^8.8",
>
>        "drupal/mask": "^2.0@alpha",
>
>        "drupal/recaptcha": "^3.0",
>
>        "drupal/webform": "^6.1"
>
>    },
>
>    "conflict": {
>
>        "drupal/drupal": "*"
>
>    },
>
>    "minimum-stability": "dev",
>
>    "prefer-stable": true,
>
>    "config": {
>
>        "sort-packages": true
>
>    },
>
>    "extra": {
>
>        "drupal-scaffold": {
>
>            "locations": {
>
>                "web-root": "web/"
>
>            }
>
>        },
>
>        "installer-paths": {
>
>            "web/core": [
>
>                "type:drupal-core"
>
>            ],
>
>            "web/libraries/{$name}": [
>
>                "type:drupal-library"
>
>            ],
>
>            "web/modules/contrib/{$name}": [
>
>                "type:drupal-module"
>
>            ],
>
>            "web/profiles/contrib/{$name}": [
>
>                "type:drupal-profile"
>
>            ],
>
>            "web/themes/contrib/{$name}": [
>
>                "type:drupal-theme"
>
>            ],
>
>            "drush/Commands/contrib/{$name}": [
>
>                "type:drupal-drush"
>
>            ],
>
>            "web/modules/custom/{$name}": [
>
>                "type:drupal-custom-module"
>
>            ],
>
>            "web/themes/custom/{$name}": [
>
>                "type:drupal-custom-theme"
>
>            ]
>
>        },
>
>        "drupal-core-project-message": {
>
>            "include-keys": [
>
>                "homepage",
>
>                "support"
>
>            ],
>
>            "post-create-project-cmd-message": [
>
>                "<bg=blue;fg=white>                                                         </>",
>
>                "<bg=blue;fg=white>  Congratulations, you’ve installed the Drupal codebase  </>",
>
>                "<bg=blue;fg=white>  from the drupal/recommended-project template!          </>",
>
>                "<bg=blue;fg=white>                                                         </>",
>
>                "",
>
>                "<bg=yellow;fg=black>Next steps</>:",
>
>                "  * Install the site: https://www.drupal.org/docs/8/install",
>
>                "  * Read the user guide: https://www.drupal.org/docs/user_guide/en/index.html",
>
>                "  * Get support: https://www.drupal.org/support",
>
>                "  * Get involved with the Drupal community:",
>
>                "      https://www.drupal.org/getting-involved",
>
>                "  * Remove the plugin that prints this message:",
>
>                "      composer remove drupal/core-project-message"
>
>            ]
>
>        }
>
>    }
>
>}
>
>