node: could not initialize ICU (check NODE_ICU_DATA or --icu-data-dir parameters)

You need to run npm install including the full-icu package. It's full-icu's postinstall step which downloads the appropriate bits for the currently executing node. Note that multiple files may show up in the full-icu directory, that's OK.

If you already had full-icu installed, but upgraded Node.js in between:

npm rebuild

fixes the issue.

If you already had full-icu installed, but did upgrade node in between:

npm rebuild does fix the issue.