How to create a valid issuer?

Hello, I’m having a problem with the validation of a certificate, I’m able to issue a certificate to the ethereum ropsten chain, but when I try to validate it I keep getting this error:

I’ve also tried changing the issuer but I get instead an error like this at the verifier:

ErrorNot a valid Blockcerts credential. Please check with the issuer or recipient that has provided this credential.

I’ll leave here also the link to my issuer json

I would like to know what is wrong with my issuer profile.

I would appreciate a lot any kinds of help!!

The error you are getting is because the transaction data (the blockchain transaction that is) cannot be retrieved.
It is either because you are testing your cert too early after issuance and the transaction has not propagated on the blockchain (not enough confirmations) or because the transaction referenced does not exist but that would be quite surprising since I am not aware of such a (major) issue.

As far as I can tell your issuer profile looks correct.

When this error comes up

ErrorNot a valid Blockcerts credential. Please check with the issuer or recipient that has provided this credential.

You may have access to a more explicit, technical error in the developer console of your browser. You could have a look at that.