- - Requires Erlang 24.2+ (dropping Erlang 23 support); nodes on older Erlang will refuse to start.
- - Nodes now default to 65 536 concurrent connections and a capped open‑file handle limit; overriding requires OS and ERL_MAX_PORTS configuration changes.
- - Core enhancements include configurable default queue type per vhost, authentication timeout settings for MQTT and STOMP, and multiple robustness and bug‑fix updates (free‑disk monitor, TLS hostname verification, stream validation, etc).