I had this error setting up Webpack:
SyntaxError: Invalid regular expression: /(\p{Uppercase_Letter}+|\p{Lowercase_Letter}|\d)(\p{Uppercase_Letter}+)/: Invalid escape
This was caused by some inconsistency between node version and webpack.
npm install webpack@4.42.0 webpack-cli@3.3.11 webpack-dev-server@3.10.3 --save-dev
After this my command worked again!
npm run scripts:build