'cross-env' is not recognized as an internal or external command,
You need to make cross-env working globally instead of having it in the project. 1) remove node_modules folder 2) run npm install --global cross-env 3) remove "cross-env": "^5.0.1", from package.json file devDependencies section. Actually, you can skip this step and keep package.json intact. If you prefer. 4) run npm install --no-bin-links 5) run npm run dev