The `node:` module prefix requires Node 14.18+ (and Zen targets Node 16+). The reporter was on an old Node where `node:async_hooks` did not exist, so the firewall's context storage module failed at require time. Fix: run on Node 16 or newer (a maintainer verified `node:16-alpine` in Docker works). If you see `Cannot find module 'node:...'` from any instrumenting library, your Node is too old for the `node:` prefix, upgrade Node before debugging anything else.