8: The message receiver's SDK is too old and cannot recognize this message.
7: The message is null or exceeds 32 KB in length.
6: The user ID is invalid.
2: A timeout occurs when sending the peer-to-peer message. 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.
5: The method call frequency exceeds the limit of 180 calls every three seconds (channel and peer messages taken together).
1: The sender fails to send the peer-to-peer message.