Identify the MQTTS Failure
The PubSub configuration fails while connecting to the EMQX broker over TLS. The configuration test reports Error: Failed to connect the MQTT broker: MqttException (0). After applying the configuration and starting the connection, the runtime reports Error connecting to ssl://m11f8e01.ala.us-east-1.emqxssl.com:8883: MqttException (0).
| Stage | Observed result | Confirmed detail |
|---|---|---|
| Configuration test | MqttException (0) |
Broker connection fails |
| Runtime start | MqttException (0) |
Target uses ssl:// on port 8883
|
Confirm the Release Limitation
The confirmed root cause is a defect in the current simulation-server release: that release does not work properly with MQTTS. This explains why both the configuration test and runtime connection fail against the TLS endpoint. The evidence does not identify the affected release number or establish that unencrypted MQTT is affected.
Apply the Supported Resolution
- Confirm that the configured broker URI is
ssl://m11f8e01.ala.us-east-1.emqxssl.com:8883and that the failure matchesMqttException (0). - Obtain the beta release containing the MQTTS correction through the product provider's official support channel. No public download location or release identifier is supplied in the evidence.
- Retest the PubSub configuration, apply it, and start the connection. Verify both stages complete without
MqttException (0).
Handle the EMQX CA Certificate
EMQX provides a downloadable CA certificate, but the available evidence does not confirm whether this simulation-server release requires manual CA installation or where its trust store is located. Do not infer a certificate directory. First apply the release containing the MQTTS fix; if the corrected release then reports a certificate or trust error, obtain its documented certificate-import procedure from the product provider.
FAQ
Why does PubSub return MqttException (0) with EMQX?
The confirmed cause is that the current simulation-server release does not work properly with MQTTS. A beta release is available to correct that behavior.
Does MqttException (0) prove the EMQX CA certificate is missing?
No. The evidence associates the failure with the release's MQTTS defect and does not identify a missing CA certificate as the cause.
How do I verify the MQTTS fix?
After installing the corrected release, test the configuration and then apply and start it against ssl://m11f8e01.ala.us-east-1.emqxssl.com:8883. Both operations must complete without MqttException (0).