My client is not getting any messages. What to do now?

There can be multiple reasons for your client to not get any message. Please double check if your client is connected to the broker and is subscribed to the topic you want to receive messages from. You can double check this using the HiveMQ Control Center. 

Check the connection state of the client

Navigate to the Control Center and select the Clients view. Generate a new Snapshot and search for the client using its client ID. If the client is not listed then the client does not have a connection with the cluster. If the client is listed but it is highlighted red, then the client does have a persistent session at the broker, but is currently not connected.

In both cases: Please review the connection configuration on the client side and connect the client. A possible root cause could be that HiveMQ Cloud does not yet know the credentials the client is using to connect to the broker.