Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires ui-awesome/html ^0.2 -> satisfiable by ui-awesome/html[0.2.0]. - ui-awesome/html 0.2.0 requires ui-awesome/html-helper ^0.1 -> found ui-awesome/html-helper[0.1.0, 0.1.1, 0.1.2] but it conflicts with your root composer.json require (^0.2). Problem 2 - Root composer.json requires ui-awesome/html-attribute ^0.1 -> satisfiable by ui-awesome/html-attribute[0.1.0, 0.1.1, 0.1.2, 0.1.3]. - ui-awesome/html-attribute[0.1.0, ..., 0.1.3] require ui-awesome/html-helper ^0.1 -> found ui-awesome/html-helper[0.1.0, 0.1.1, 0.1.2] but it conflicts with your root composer.json require (^0.2). Problem 3 - Root composer.json requires ui-awesome/html-concern ^0.1 -> satisfiable by ui-awesome/html-concern[0.1.0, 0.1.1, 0.1.2]. - ui-awesome/html-concern[0.1.0, ..., 0.1.2] require ui-awesome/html-helper ^0.1 -> found ui-awesome/html-helper[0.1.0, 0.1.1, 0.1.2] but it conflicts with your root composer.json require (^0.2).