# Class BSV::Network::BlockHeader::InvalidHeaderError <a id="class-BSV-Network-BlockHeader-InvalidHeaderError"></a>

**Inherits:** `BSV::Wallet::Error`

Raised when the byte string handed to {.parse} is not exactly the 80-byte
header length. Carried as a typed error so callers can distinguish a
structural reject from an unrelated `StandardError`; the chain tracker simply
treats any raised failure as `false`.