Your lock file does not contain a compatible set of packages. Please run composer update. Problem 1 - ocramius/package-versions is locked to version 1.2.0 and an update of this package was not requested. - ocramius/package-versions 1.2.0 requires composer-plugin-api ^1.0 -> found composer-plugin-api[2.1.0] but it does not match the constraint. Problem 2 - ocramius/package-versions 1.2.0 requires composer-plugin-api ^1.0 -> found composer-plugin-api[2.1.0] but it does not match the constraint. - ocramius/proxy-manager 2.0.4 requires ocramius/package-versions ^1.0 -> satisfiable by ocramius/package-versions[1.2.0]. - ocramius/proxy-manager is locked to version 2.0.4 and an update of this package was not requested.