Unable to sign transaction (testnet)

You’re right.

Common prefixies for testnet addresses are m* and n*. The Electrum wallet actually generates such addresses.

However, my bitcoin core generates addresses with a 2* as a prefix which is also valid for the testnet. When I look at the difference between the two types it appears that they are not the same type of key:

I saw posts on this blog where people successfully issue certificates with a m* address but I didn’t see any documentation specifying that cert-issuer can/can’t handle Pay to script hash (P2SH) transactions.

Do you think that P2SH confuses cert-issuer? I’m stuck here, what do you suppose I try to finally issue on the testnet?

Thanks,
Florent.