The combined Binance stream interleaves the kline payloads with
subscription acks, heartbeats and error objects. The example pulled
k = payload.get("k", {}) and immediately did float(k.get("c")) — for
any non-kline frame k is {}, k.get("c") is None, and float(None) raises
TypeError, crashing the script the moment it connects.
Skip frames without a kline payload (no "k" object, or no "c" close
field) with a debug log line, matching the C2 fix on the Rust adapter.
kingchenc
783e40069d