Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires doctrine/doctrine-bundle ^1.12.0|^2.0 -> satisfiable by doctrine/doctrine-bundle[1.12.0, ..., 1.12.13, 2.0.0, ..., 2.11.1]. - Conclusion: don't install doctrine/persistence 2.5.5 (conflict analysis result) - Conclusion: don't install doctrine/persistence 2.5.7 (conflict analysis result) - Conclusion: install symfony/doctrine-bridge v3.4.47 (conflict analysis result) - doctrine/common v2.9.0 requires doctrine/persistence ^1.0 -> found doctrine/persistence[v1.0.0, ..., 1.3.8] but it conflicts with your root composer.json require (^2.5.1). - doctrine/common[v2.10.0, ..., 2.12.0] require doctrine/persistence ^1.1 -> found doctrine/persistence[v1.1.0, ..., 1.3.8] but it conflicts with your root composer.json require (^2.5.1). - doctrine/common[2.13.0, ..., 2.13.3] require doctrine/persistence ^1.3.3 -> found doctrine/persistence[1.3.3, ..., 1.3.8] but it conflicts with your root composer.json require (^2.5.1). - Conclusion: don't install doctrine/persistence 2.5.4 (conflict analysis result) - symfony/doctrine-bridge[v3.4.10, ..., v3.4.47] require doctrine/common ~2.4 -> satisfiable by doctrine/common[v2.4.0, ..., 2.13.3]. - doctrine/persistence 2.5.1 conflicts with doctrine/common v2.8.1. - doctrine/persistence 2.5.1 conflicts with doctrine/common v2.7.3. - doctrine/persistence 2.5.1 conflicts with doctrine/common v2.6.2. - doctrine/persistence 2.5.1 conflicts with doctrine/common v2.5.3. - Root composer.json requires doctrine/persistence ^2.5.1 -> satisfiable by doctrine/persistence[2.5.1, ..., 2.5.7].