The following return codes from backward and forward calls can be used for diagnosing your miner:
NoReturn = 0; Default value.
Success = 1; Succesfull query.
Timeout = 2; Request timeout.
Backoff = 3; Call triggered a backoff.
Unavailable = 4; Endpoint not available.
NotImplemented = 5; Modality not implemented.
EmptyRequest = 6; Request is empty.
EmptyResponse = 7; Response is empty.
InvalidResponse = 8; Request is invalid.
InvalidRequest = 9; Response is invalid.
RequestShapeException = 10; Request has an invalid shape.
ResponseShapeException = 11; Response has an invalid shape.
RequestSerializationException = 12; Request failed to serialize.
ResponseSerializationException = 13; Response failed to serialize.
RequestDeserializationException = 14; Request failed to deserialize.
ResponseDeserializationException = 15; Response failed to deserialize.
NotServingNucleus = 16; Receiving Neuron is not serving a Nucleus to query.
NucleusTimeout = 17; Processing on the Server side timed out.
NucleusFull = 18; Returned when the processing queue on the Server is full.
RequestIncompatibleVersion = 19; The request handler is incompatible with the request version. Request from Validator to Server.
ResponseIncompatibleVersion = 20; The request handler is incompatible with the request version. Response from Server to Validator.
SenderUnknown = 21; Requester is not known by the receiver.
UnknownException = 22; Unknown exception.
Unauthenticated = 23; Authentication failed.