EHPDFHeadlessTimestampError

Exception in HPDFHeadlessTimestamp for invalid requests or responses, missing trust configuration, unavailable OpenSSL timestamp symbols, failed TSA signature or chain authentication, imprint or nonce mismatches, malformed DER, evidence failures, and byte-budget violations

Cancellation raises EHPDFOperationCancelled and transport callbacks preserve their own exceptions

Failed timestamp authentication aborts CMS signing and prevents incremental PDF publication