#Node.js

error:0308010C digital envelope routines::unsupported — Fixing Node 17+ Breakage in Older Projects

Node 17+ crashes webpack 4 builds with error:0308010C:digital envelope routines::unsupported because OpenSSL 3.0 removed MD4. Three fixes compared: --openssl-legacy-provider quick unblock, upgrading to webpack 5 as the real fix, and pinning Node 16 as a stopgap.

ECONNREFUSED: Connection Refused — 5 Causes Explained (Including Docker)

Node, Java, or curl reporting connect ECONNREFUSED 127.0.0.1:3306? It means nothing is listening on that port. Covers service not running, wrong port, 127.0.0.1-only binding, Docker container networking, and firewall REJECT rules — with ss/lsof diagnostic commands.

Cannot find module: 6 Reasons Node.js Can't Find Your Module (and How to Fix Each)

Node.js ERR_MODULE_NOT_FOUND or Cannot find module errors decoded: require vs import path rules, node_modules corruption, case sensitivity, ESM/CommonJS mixing, monorepo workspaces — with fix commands for each.