4: The message is null or exceeds 32 KB in length.
5: The user is not in the channel.
2: 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.
3: The method call frequency exceeds the limit of 180 calls every three seconds (channel and peer messages taken together).
1: Common failure. The user fails to send the channel message.