Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires ghostwriter/coding-standard dev-main -> satisfiable by ghostwriter/coding-standard[dev-main]. - ghostwriter/coding-standard dev-main requires ext-gd * -> it is missing from your system. Install or enable PHP's gd extension. To enable extensions, verify that they are enabled in your .ini files: - C:\tools\php\php.ini You can also run `php --ini` in a terminal to see which files are used by PHP in CLI mode. Alternatively, you can run Composer with `--ignore-platform-req=ext-gd` to temporarily ignore these required extensions. Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.