I can’t issue certificates that contains the displayHtml attribute.
I get this error when trying to sign a certificate containing this field:
WARNING - Caught exception trying provider <bound method BlockrIOBroadcaster.broadcast_tx of <cert_issuer.bitcoin.connectors.BlockrIOBroadcaster object at 0x7fbecc918e80>>. Trying another. Exception=Expecting value: line 1 column 1 (char 0)
I opened an issue here: https://github.com/blockchain-certificates/cert-issuer/issues/85