Your requirements could not be resolved to an installable set of packages. Problem 1 - darkaonline/l5-swagger 8.1.0 requires symfony/yaml ^5.0 -> found symfony/yaml[v5.0.0-BETA1, ..., 5.4.x-dev] but these were not loaded, likely because it conflicts with another require. - badaso/core dev-bugfix/issues requires darkaonline/l5-swagger 8.1 -> satisfiable by darkaonline/l5-swagger[8.1.0]. - Root composer.json requires badaso/core dev-bugfix/issues -> satisfiable by badaso/core[dev-bugfix/issues].