# Error issuing certificate **URL:** \ **Category:** Technical\ **Created:** [July 3, 2019, 6:17am UTC](https://community.blockcerts.org/t/error-issuing-certificate/1998 "2019-07-03T06:17:51Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![mylliswang](https://avatars.discourse-cdn.com/v4/letter/m/f475e1/32.png) [@mylliswang](https://community.blockcerts.org/u/mylliswang)\ **Post date:** [July 3, 2019, 6:17am UTC](https://community.blockcerts.org/t/error-issuing-certificate/1998/1 "2019-07-03T06:17:51Z")
Hi, I am trying to issue certificates fllowing the steps in [https://github.com/blockchain-certificates/cert-issuer/blob/master/README.md](https://github.com/blockchain-certificates/cert-issuer/blob/master/README.md) when it comes to the last command: cert-issuer -c /etc/cert-issuer/conf.ini I get the following error. I already tried running in an environment but it is not working WARNING - Your app is configured to skip the wifi check when the USB is plugged in. Read the documentation to ensure this is what you want, since this is less secure INFO - This run will try to issue on the bitcoin\_regtest chain Traceback (most recent call last): File “/usr/bin/cert-issuer”, line 11, in load\_entry\_point(‘cert-issuer==2.0.17’, ‘console\_scripts’, ‘cert-issuer’)() File “/usr/lib/python3.6/site-packages/cert\_issuer/ **main**.py”, line 17, in cert\_issuer\_main issue\_certificates.main(parsed\_config) File “/usr/lib/python3.6/site-packages/cert\_issuer/issue\_certificates.py”, line 34, in main from cert\_issuer.blockchain\_handlers import bitcoin File “/usr/lib/python3.6/site-packages/cert\_issuer/blockchain\_handlers/bitcoin/ **init**.py”, line 7, in from cert\_issuer.blockchain\_handlers.bitcoin.connectors import BitcoinServiceProviderConnector, MockServiceProviderConnector File “/usr/lib/python3.6/site-packages/cert\_issuer/blockchain\_handlers/bitcoin/connectors.py”, line 13, in from pycoin.serialize import b2h, b2h\_rev, h2b ImportError: cannot import name ‘b2h’ bash-4.3# ---
**Author:** ![faustow](https://sea2.discourse-cdn.com/flex016/user_avatar/community.blockcerts.org/faustow/32/603_2.png) [@faustow](https://community.blockcerts.org/u/faustow)\ **Post date:** [July 4, 2019, 9:03pm UTC](https://community.blockcerts.org/t/error-issuing-certificate/1998/2 "2019-07-04T21:03:59Z")
The root issue for this is that pycoin released a new version (after almost 2 years) this week. In this new version there are a lot of non-backwards compatible changes that break cert-issuer in multiple places. Please check [https://github.com/blockchain-certificates/cert-issuer/pull/144](https://github.com/blockchain-certificates/cert-issuer/pull/144) for reference but until that gets merged or fixed some other way you can get away by locking pycoin to v0.80. ---
**Author:** ![mylliswang](https://avatars.discourse-cdn.com/v4/letter/m/f475e1/32.png) [@mylliswang](https://community.blockcerts.org/u/mylliswang)\ **Post date:** [July 6, 2019, 5:41pm UTC](https://community.blockcerts.org/t/error-issuing-certificate/1998/3 "2019-07-06T17:41:30Z")
@faustow Thanks it works! I uninstalled v0.90 and instead used v0.80 and that solve all the issues, now is issuing the certificates. ---
**Author:** ![EsaieBellevue](https://avatars.discourse-cdn.com/v4/letter/e/54ee81/32.png) [@EsaieBellevue](https://community.blockcerts.org/u/EsaieBellevue)\ **Post date:** [July 10, 2019, 8:06am UTC](https://community.blockcerts.org/t/error-issuing-certificate/1998/4 "2019-07-10T08:06:24Z")
@mylliswang Comment désinstallé la version 0.8 de pycoin? Merci ---
**Author:** ![mylliswang](https://avatars.discourse-cdn.com/v4/letter/m/f475e1/32.png) [@mylliswang](https://community.blockcerts.org/u/mylliswang)\ **Post date:** [July 10, 2019, 8:23am UTC](https://community.blockcerts.org/t/error-issuing-certificate/1998/5 "2019-07-10T08:23:33Z")
use this command: pip uninstall pycoin==0.9 and then pip install pycoin==0.8 (if you are using pip3 then use pip3 uninstall pycoin==0.9) ---
**Author:** ![EsaieBellevue](https://avatars.discourse-cdn.com/v4/letter/e/54ee81/32.png) [@EsaieBellevue](https://community.blockcerts.org/u/EsaieBellevue)\ **Post date:** [July 10, 2019, 9:16am UTC](https://community.blockcerts.org/t/error-issuing-certificate/1998/6 "2019-07-10T09:16:47Z")
@mylliswang it does not work, I use debian 9 . pip install pycoin==0.8 Collecting pycoin==0.8 Could not find a version that satisfies the requirement pycoin==0.8 (from versions: 0.50.macosx-10.9-intel, 0.1, 0.2, 0.4, 0.9.20190630, 0.11, 0.12, 0.13, 0.14, 0.15, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.41, 0.42, 0.50, 0.51, 0.52, 0.60, 0.61, 0.62, 0.70, 0.75, 0.76, 0.77, 0.80, 0.90.20190630) No matching distribution found for pycoin==0.8 ![image](https://us1.discourse-cdn.com/flex016/uploads/blockcerts/original/1X/1cea6e17e1003e6c25e9af6cdfddbe61bcecc6b7.png) ---
**Author:** ![EsaieBellevue](https://avatars.discourse-cdn.com/v4/letter/e/54ee81/32.png) [@EsaieBellevue](https://community.blockcerts.org/u/EsaieBellevue)\ **Post date:** [July 10, 2019, 9:26am UTC](https://community.blockcerts.org/t/error-issuing-certificate/1998/7 "2019-07-10T09:26:04Z")
@mylliswang ![image](https://us1.discourse-cdn.com/flex016/uploads/blockcerts/original/1X/0791f53defb84c5ebc35293881a3fdcd0d9a13d4.png) ---
**Author:** ![mylliswang](https://avatars.discourse-cdn.com/v4/letter/m/f475e1/32.png) [@mylliswang](https://community.blockcerts.org/u/mylliswang)\ **Post date:** [July 18, 2019, 4:38am UTC](https://community.blockcerts.org/t/error-issuing-certificate/1998/8 "2019-07-18T04:38:42Z")
I think you need to use pycoin==0.80 ---
**Author:** ![EsaieBellevue](https://avatars.discourse-cdn.com/v4/letter/e/54ee81/32.png) [@EsaieBellevue](https://community.blockcerts.org/u/EsaieBellevue)\ **Post date:** [July 19, 2019, 6:50am UTC](https://community.blockcerts.org/t/error-issuing-certificate/1998/9 "2019-07-19T06:50:54Z")
Thank you @mylliswang