The package reference to core-js is invalid .
$ npm install babylon --save-dev
npm ERR! Windows_NT 6.1.7601
npm ERR! argv "C:\Program Files\nodejs\node.exe" "C:\Users\Gabi\AppData\Roaming\npm\node_modules\npm\bin\npm-cli.js" "install" "babylon" "--save-dev"
npm ERR! node v6.2.0
npm ERR! npm v3.8.8
npm ERR! No compatible version found: core-js@^2.4.0
npm ERR! Valid install targets:
npm ERR! 2.3.0, 2.2.2, 2.2.1, 2.2.0, 2.1.5, 2.1.4, 2.1.3, 2.1.2, 2.1.1, 2.1.0, 2.0.3, 2.0.2, 2.0.1, 2.0.0, 2.0.0-beta.2, 2.0.0-beta, 2.0.0-alpha, 1.2.6, 1.2.5, 1.2.4, 1.2.3, 1.2.2, 1.2.1, 1.2.0, 1.1.4, 1.1.3, 1.1.2, 1.1.1, 1.1.0, 1.0.1, 1.0.0, 0.9.18, 0.9.17, 0.9.16, 0.9.15, 0.9.14, 0.9.13, 0.9.12, 0.9.11, 0.9.10, 0.9.9, 0.9.8, 0.9.7, 0.9.6, 0.9.5, 0.9.4, 0.9.3, 0.9.2, 0.9.1, 0.9.0, 0.8.4, 0.8.3, 0.8.2, 0.8.1, 0.8.0, 0.7.2, 0.7.1, 0.7.0, 0.6.1, 0.6.0, 0.5.4, 0.5.3, 0.5.2, 0.5.1, 0.5.0, 0.4.10, 0.4.9, 0.4.8, 0.4.7, 0.4.6, 0.4.5, 0.4.4, 0.4.3, 0.4.2, 0.4.1, 0.4.0, 0.3.3, 0.3.2, 0.3.1, 0.3.0, 0.2.5, 0.2.4, 0.2.3, 0.2.2, 0.2.1, 0.2.0, 0.1.5, 0.1.4, 0.1.3, 0.1.2, 0.1.1, 0.0.9, 0.0.8, 0.0.7, 0.0.5, 0.0.4, 0.0.3
npm ERR!
npm ERR!
npm ERR! If you need help, you may report this error at:
npm ERR! https://github.com/npm/npm/issues
npm ERR! Please include the following file with any support re