# Certificate Verification Error on Ethereum Ropsten chain

**URL:** <https://community.blockcerts.org/t/certificate-verification-error-on-ethereum-ropsten-chain/1661>\
**Category:** Support\
**Created:** [January 29, 2019, 4:47pm UTC](https://community.blockcerts.org/t/certificate-verification-error-on-ethereum-ropsten-chain/1661 "2019-01-29T16:47:42Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![ntydrm](https://avatars.discourse-cdn.com/v4/letter/n/db5fbb/32.png) [@ntydrm](https://community.blockcerts.org/u/ntydrm)\
**Post date:** [January 29, 2019, 4:47pm UTC](https://community.blockcerts.org/t/certificate-verification-error-on-ethereum-ropsten-chain/1661/1 "2019-01-29T16:47:43Z")

</div>

Hi,

I try to verify the certificate on [www.blockcert.org](http://www.blockcert.org), and encountered an error which says  
“Transaction occured at time when issuing address was not considered valid.”  
I refer to the discussion the post " [Verifier - Checking authenticity [FAIL]](https://community.blockcerts.org/t/verifier-checking-authenticity-fail/245/6) "

I use github to store my issuer.json(use create-issuer in cert-tools), the access to files is all OK. And I also modified the issuer’s create time to one day earlier than the creating time.

However, the same error info is still there.  
Could anyone please help give some advice to fix the problem?

Thanks for your help.

---

<div class="post-metadata">

**Author:** ![aronning](https://avatars.discourse-cdn.com/v4/letter/a/47e85d/32.png) [@aronning](https://community.blockcerts.org/u/aronning)\
**Post date:** [January 30, 2019, 9:28pm UTC](https://community.blockcerts.org/t/certificate-verification-error-on-ethereum-ropsten-chain/1661/2 "2019-01-30T21:28:26Z")

</div>

Check out this recent post, apparently a recent change fixes that issue:

> [@\[RESOLVED\] "Transaction occurred at time when issuing address was not considered valid."](https://community.blockcerts.org/t/resolved-transaction-occurred-at-time-when-issuing-address-was-not-considered-valid/1592):
>
> Hi everyone, Recently I am trying to deploy my first blockcert from the scratch. And here is roughly what I have done: Generated a wallet address (as well as the private key) on the bitcoin testate Created an issuer file and post it to [https://raw.githubusercontent.com/ppfish45/Blockcerts\_test/master/test.json](https://raw.githubusercontent.com/ppfish45/Blockcerts_test/master/test.json) Batched two unsigned certificates with this issuer\_id above Issue the two certificates by cert-issuer Upload the signed certificates onto the [blockcerts.org](http://blockcerts.org) to see whether …