Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires phpstan/phpstan ^1.10 -> satisfiable by phpstan/phpstan[1.10.0, ..., 1.10.54]. - phpstan/phpstan[1.10.0, ..., 1.10.54] require php ^7.2|^8.0 -> your php version (7.1.33) does not satisfy that requirement. Problem 2 - Root composer.json requires wdes/coding-standard ^3.3.2 -> satisfiable by wdes/coding-standard[v3.3.2]. - wdes/coding-standard v3.3.2 requires php ^7.2 || ^8.0 -> your php version (7.1.33) does not satisfy that requirement.