invalid block: Header.DataHash is different from Hash(block.

Error message

invalid block: Header.DataHash is different from Hash(block.Data)

What it means

ValidateJoinBlock guard: the SHA-256 hash of the block's data does not match Header.DataHash, so the block's integrity is broken — data was modified after the header was computed, or the block is corrupt. The join request is rejected as invalid.

Source

Thrown at orderer/common/channelparticipation/validator.go:38

)

// ValidateJoinBlock checks whether this block can be used as a join block for the channel participation API.
// It returns the channel ID.
// It verifies that it is not a system channel by checking that consortiums config does not exist.
// It verifies it is an application channel by checking that the application group exists.
// It returns an error when it cannot be used as a join-block.
func ValidateJoinBlock(configBlock *cb.Block) (channelID string, err error) {
	if !protoutil.IsConfigBlock(configBlock) {
		return "", errors.New("block is not a config block")
	}

	if configBlock.Metadata == nil || len(configBlock.Metadata.Metadata) == 0 {
		return "", errors.New("invalid block: does not have metadata")
	}

	dataHash := protoutil.ComputeBlockDataHash(configBlock.Data)
	if !bytes.Equal(dataHash, configBlock.Header.DataHash) {
		return "", errors.New("invalid block: Header.DataHash is different from Hash(block.Data)")
	}

	envelope, err := protoutil.ExtractEnvelope(configBlock, 0)
	if err != nil {
		return "", err
	}

	cryptoProvider := factory.GetDefault()
	bundle, err := channelconfig.NewBundleFromEnvelope(envelope, cryptoProvider)
	if err != nil {
		return "", err
	}

	channelID = bundle.ConfigtxValidator().ChannelID()

	// Check channel type
	_, isSystemChannel := bundle.ConsortiumsConfig()
	if isSystemChannel {

View on GitHub (pinned to 2736b63f8f)

Solutions

Re-obtain the config block from its authoritative source
Check for transport-level corruption when the block was exported/copied

Defensive patterns

Strategy: validation

When it happens

Trigger: Thrown at orderer/common/channelparticipation/validator.go:38 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/6c60c6591c275e9c. Report an issue: GitHub.