(Reproducible) MQTT nodes show disconnected when server/message/topic contains an #

If you edit an MQTT node (in or out) and in the Server section select the Messages tab and in Messages sent on connection (birth message) or Message sent on an unexpected disconnection (will message) put a # (pound sign) in the topic, when you deploy the node will only show disconnected.

This happens in NR v1.3.5 and NR 2.2.2

Interestingly it does not happen (that I have been able to cause) if you add it to the topic in Message sent before disconnecting (close message)

Moral: If your MQTT nodes show disconnected all the time, check those areas for a # in the topic.

Issue opened: MQTT nodes show 'disconnected' if 'birth message' or 'will message' topic contains a '#' (pound sign) · Issue #3557 · node-red/node-red · GitHub

1 Like

It's my understanding only the subscription can contain wildcards and you're publishing with both of those messages. Still, the input should be checked and disallowed.