MQTT Client Error Codes

Error code
(Decimal)
Error code
(Hex)
Meaning
0 0x0 No Error
1 0x1 Connection Refused: Unacceptable protocol version
10 0xa Timeout waiting for SUBACK
11 0xb Timeout waiting for UNSUBACK
12 0xc Timeout waiting for PINGRESP
13 0xd Malformed Remaining Length
14 0xe Problem with the underlying communication port
15 0xf Address could not be parsed
16 0x10 Malformed received MQTT packet
17 0x11 Subscription failure
18 0x12 Payload decoding failure
19 0x13 Failed to compile a Decoder
2 0x2 Connection Refused: Identifier rejected
20 0x14 The received MQTT packet type is not supported on this client
3 0x3 Connection Refused: Server Unavailable
4 0x4 Connection Refused: Bad username or password
5 0x5 Connection Refused: Authorization error
6 0x6 Connection lost or bad
7 0x7 Timeout waiting for Length bytes
8 0x8 Timeout waiting for PayLoad
9 0x9 Timeout waiting for CONNACK