The LND Emulator Utility: A Comprehensive Tool for Lightning Network Development

  "payment_error": "TemporaryChannelFailure: channel 12345x has insufficient balance",
  "payment_preimage": "",
  "payment_route": null
Getting started (concise checklist)

Install lnd and bitcoind (or choose an emulator implementation).
Configure lnd for regtest with RPC credentials and appropriate ports.
Start bitcoind in regtest and generate initial blocks to fund wallets.
Launch multiple lnd instances, create wallets, and connect peers.
Open channels and run payment scenarios; capture logs and inspect state.

Historically, software vendors used HASP or Hardlock USB dongles to prevent unauthorized use. The LND Emulator Utility was developed by a cracking group named "LND" (Legends Never Die) to emulate these physical keys.