The message is null or exceeds 32 KB in length.
The user is not in the channel.
The SDK does not receive a response from the server in five seconds. The current timeout is set as five seconds. The current login timeout is set as six seconds. Possible reasons: The user is in the ABORTED or RECONNECTING state.
The method call frequency exceeds the limit of 60 queries per second (channel and peer messages taken together).
Common failure. The user fails to send the channel message.