# Latest **URL:** https://community.blockcerts.org/latest.md [Latest](https://community.blockcerts.org/latest.md) · [Categories](https://community.blockcerts.org/categories.md) --- ## [FAQ - technical issues](https://community.blockcerts.org/t/faq-technical-issues/3251)
**Author:** [@lemoustachiste](https://community.blockcerts.org/u/lemoustachiste)\ **Replies:** 0\ **Last updated:** [July 11, 2022, 2:20pm UTC](https://community.blockcerts.org/t/faq-technical-issues/3251 "2022-07-11T14:20:59Z")
AttributeError: ‘CertificateBatchHandler’ object has no attribute ‘certificates\_to\_issue’ Solution: Error: with cert\_issuer -c conf.ini(AttributeError: ‘CertificateBatchHandler’ object has no attribute 'certificates\_t… --- ## [Welcome to the Blockcerts community](https://community.blockcerts.org/t/welcome-to-the-blockcerts-community/8)
**Author:** [@system](https://community.blockcerts.org/u/system)\ **Replies:** 0\ **Last updated:** [March 8, 2017, 11:37pm UTC](https://community.blockcerts.org/t/welcome-to-the-blockcerts-community/8 "2017-03-08T23:37:13Z")
Blockcerts is an open standard for creating, issuing, viewing, and verifying blockchain-based digital records. These records are registered on the blockchain, cryptographically signed, tamper-proof, and shareable. The go… --- ## [Custom Certificate](https://community.blockcerts.org/t/custom-certificate/2983)
**Author:** [@sreenumalae](https://community.blockcerts.org/u/sreenumalae)\ **Replies:** 11\ **Last updated:** [April 4, 2026, 2:45am UTC](https://community.blockcerts.org/t/custom-certificate/2983 "2026-04-04T02:45:23Z")
Instead of creating a certificate using different logos. I have an LMS where I create a certificate. Is it possible to pass that certificate to BlockCerts and authenticate that certificate using blockchain? --- ## [\[Blockcerts Wallet\] IOS does not allow v3 certificates](https://community.blockcerts.org/t/blockcerts-wallet-ios-does-not-allow-v3-certificates/3942)
**Author:** [@Berthvid](https://community.blockcerts.org/u/Berthvid)\ **Replies:** 5\ **Last updated:** [January 15, 2026, 2:32pm UTC](https://community.blockcerts.org/t/blockcerts-wallet-ios-does-not-allow-v3-certificates/3942 "2026-01-15T14:32:51Z")
I noticed that I can add my certificates into the blockcerts wallet for android, but when trying to add them in the IOS app, it says “This is not a valid link” or something like this. --- ## [\[Identity verification\]Why derive and compare issuing address with transaction?](https://community.blockcerts.org/t/identity-verification-why-derive-and-compare-issuing-address-with-transaction/3538)
**Author:** [@linear](https://community.blockcerts.org/u/linear)\ **Replies:** 2\ **Last updated:** [November 17, 2025, 4:50pm UTC](https://community.blockcerts.org/t/identity-verification-why-derive-and-compare-issuing-address-with-transaction/3538 "2025-11-17T16:50:47Z")
Hello, In the cert-verifier-js, the identity verification derived issuing address from did document and compare it. I don’t know the exactly function of the step. As the DID had been written in the VC which means the DI… --- ## [Android app issue adding credential](https://community.blockcerts.org/t/android-app-issue-adding-credential/3912)
**Author:** [@Dan](https://community.blockcerts.org/u/Dan)\ **Replies:** 2\ **Last updated:** [October 24, 2025, 1:55pm UTC](https://community.blockcerts.org/t/android-app-issue-adding-credential/3912 "2025-10-24T13:55:18Z")
Hi everyone. I got a new phone from ios to android. I got the app downloaded and i shared the file. I went to add credential and imported it. Then the credential showed up but after i clicked the back arrow it wasnt the… --- ## [Demande d'aide à la communauté](https://community.blockcerts.org/t/demande-daide-a-la-communaute/3924)
**Author:** [@RAIS71](https://community.blockcerts.org/u/RAIS71)\ **Replies:** 1\ **Last updated:** [October 22, 2025, 11:19am UTC](https://community.blockcerts.org/t/demande-daide-a-la-communaute/3924 "2025-10-22T11:19:44Z")
Peut-on utiliser la blockcert pour émettre et vérifier de Certificat dans un projet php ? --- ## [Unable to add Issuer on Android 15 (flip back to same page after clicking"add issuer")](https://community.blockcerts.org/t/unable-to-add-issuer-on-android-15-flip-back-to-same-page-after-clicking-add-issuer/3921)
**Author:** [@greenhellebore](https://community.blockcerts.org/u/greenhellebore)\ **Replies:** 0\ **Last updated:** [October 6, 2025, 3:20pm UTC](https://community.blockcerts.org/t/unable-to-add-issuer-on-android-15-flip-back-to-same-page-after-clicking-add-issuer/3921 "2025-10-06T15:20:26Z")
Hello! I am on Android 15 and trying to add an issuer for my digital diploma. I entered URL & one-time code. Each time I click “Add Issuer” the “adding issuer” box will pop up, and then disappear, returning me to the sam… --- ## [Blockcerts verifier](https://community.blockcerts.org/t/blockcerts-verifier/3919)
**Author:** [@Berthvid](https://community.blockcerts.org/u/Berthvid)\ **Replies:** 1\ **Last updated:** [September 29, 2025, 6:10am UTC](https://community.blockcerts.org/t/blockcerts-verifier/3919 "2025-09-29T06:10:36Z")
Did the official blockcerts verifier got removed from the main page? I was testing the verify step after issuing my certificates and I was using this verifier to make sure I got everything right. --- ## [Looking for Best Practices for Verifying Blockcerts Without Central Authority?](https://community.blockcerts.org/t/looking-for-best-practices-for-verifying-blockcerts-without-central-authority/3857)
**Author:** [@marcellosals](https://community.blockcerts.org/u/marcellosals)\ **Replies:** 1\ **Last updated:** [July 17, 2025, 1:21pm UTC](https://community.blockcerts.org/t/looking-for-best-practices-for-verifying-blockcerts-without-central-authority/3857 "2025-07-17T13:21:45Z")
Hi everyone, I am fairly new to the Blockcerts ecosystem and fascinated by how it enables truly decentralized credential verification. I have been experimenting with issuing and verifying certificates.., but I am curiou… --- ## [Why can anyone with a link to the credential add it](https://community.blockcerts.org/t/why-can-anyone-with-a-link-to-the-credential-add-it/3856)
**Author:** [@Saadii](https://community.blockcerts.org/u/Saadii)\ **Replies:** 1\ **Last updated:** [July 17, 2025, 12:53pm UTC](https://community.blockcerts.org/t/why-can-anyone-with-a-link-to-the-credential-add-it/3856 "2025-07-17T12:53:15Z")
Hey everyone so tbh I don’t know much about blockcerts but my school used it for high school diplomas and before graduation they asked us to make accounts (or passphrases) and then add the school as issuer. I did that an… --- ## [Why add issuer option(mobile wallet) returns diferents pubkey each time](https://community.blockcerts.org/t/why-add-issuer-option-mobile-wallet-returns-diferents-pubkey-each-time/2803)
**Author:** [@Chidoman](https://community.blockcerts.org/u/Chidoman)\ **Replies:** 1\ **Last updated:** [July 9, 2025, 8:30am UTC](https://community.blockcerts.org/t/why-add-issuer-option-mobile-wallet-returns-diferents-pubkey-each-time/2803 "2025-07-09T08:30:58Z")
hi this is my profile https://6073a6b0e4e0160017ddfc72.mockapi.io/profile and my introduction url is https://6073a6b0e4e0160017ddfc72.mockapi.io/recipient you can (get) also this endpoint to see what i mean and each t… --- ## [Google Play App Not Available](https://community.blockcerts.org/t/google-play-app-not-available/3831)
**Author:** [@an\_eve](https://community.blockcerts.org/u/an_eve)\ **Replies:** 1\ **Last updated:** [June 4, 2025, 9:24am UTC](https://community.blockcerts.org/t/google-play-app-not-available/3831 "2025-06-04T09:24:07Z")
It seems the app does not exist for Goggle Play. Could you please add some info where to download the app? --- ## [No se ha podido obtener el perfil del emisor](https://community.blockcerts.org/t/no-se-ha-podido-obtener-el-perfil-del-emisor/3796)
**Author:** [@Gerataker3000](https://community.blockcerts.org/u/Gerataker3000)\ **Replies:** 2\ **Last updated:** [April 28, 2025, 3:13pm UTC](https://community.blockcerts.org/t/no-se-ha-podido-obtener-el-perfil-del-emisor/3796 "2025-04-28T15:13:36Z")
Hola comunidad, estoy configurando la emisión de certificados digitales con Blockcerts y ya generé mi plantilla en Cert Tools. Al momento de registrar el emisor, ya tengo una URL válida que apunta a mi archivo issuer.jso… --- ## [Apple App store link on https://wallet.blockcerts.org/](https://community.blockcerts.org/t/apple-app-store-link-on-https-wallet-blockcerts-org/3786)
**Author:** [@fgiacanel](https://community.blockcerts.org/u/fgiacanel)\ **Replies:** 2\ **Last updated:** [April 9, 2025, 2:13pm UTC](https://community.blockcerts.org/t/apple-app-store-link-on-https-wallet-blockcerts-org/3786 "2025-04-09T14:13:33Z")
Hello, the link for the Apple App Store in Seems to be outdated and it is not working. The correct url seems to be the one on the Blockcerts home page Is it possibile to update it on the wallet “Add the Issuer” p… --- ## [cert\_issuer.errors.InsufficientFundsError: Please add 500000000000000 wei](https://community.blockcerts.org/t/cert-issuer-errors-insufficientfundserror-please-add-500000000000000-wei/2893)
**Author:** [@sreenumalae](https://community.blockcerts.org/u/sreenumalae)\ **Replies:** 5\ **Last updated:** [April 9, 2025, 6:53am UTC](https://community.blockcerts.org/t/cert-issuer-errors-insufficientfundserror-please-add-500000000000000-wei/2893 "2025-04-09T06:53:04Z")
For the below command I’m facing the issue python3 /cert-issuer/cert\_issuer -c /cert-issuer/conf.ini WARNING - Your app is configured to skip the wifi check when the USB is plugged in. Read the documentation to ensure … --- ## [How can I create my own Context?](https://community.blockcerts.org/t/how-can-i-create-my-own-context/3769)
**Author:** [@HarukiK](https://community.blockcerts.org/u/HarukiK)\ **Replies:** 1\ **Last updated:** [April 9, 2025, 6:49am UTC](https://community.blockcerts.org/t/how-can-i-create-my-own-context/3769 "2025-04-09T06:49:16Z")
I would like to know the steps to generate an original Context. How can I create my own Context? I want to add a custom context, similar to “https://w3id.org/blockcerts/v3”, and include my own attributes inside credent… --- ## [Issue with Certificate Upload - "Invalid Credential" Error](https://community.blockcerts.org/t/issue-with-certificate-upload-invalid-credential-error/3703)
**Author:** [@sreenumalae](https://community.blockcerts.org/u/sreenumalae)\ **Replies:** 14\ **Last updated:** [April 9, 2025, 6:45am UTC](https://community.blockcerts.org/t/issue-with-certificate-upload-invalid-credential-error/3703 "2025-04-09T06:45:52Z")
I have used Cert-tools to create unsigned certificates and Cert-issuer (with Ethereum) to generate signed certificates. However, when I upload the signed certificate to the app, I encounter the following error: “Invali… --- ## [Error: SignedTransaction object has no attribute 'rawTransaction'](https://community.blockcerts.org/t/error-signedtransaction-object-has-no-attribute-rawtransaction/3604)
**Author:** [@Jorge](https://community.blockcerts.org/u/Jorge)\ **Replies:** 1\ **Last updated:** [March 27, 2025, 1:24pm UTC](https://community.blockcerts.org/t/error-signedtransaction-object-has-no-attribute-rawtransaction/3604 "2025-03-27T13:24:26Z")
Hello, I am using cert-issuer 2.0.33 to sign v2 certificates, by running the following command: cert-issuer --usb\_name KINGSTON --key\_file '/home/vboxuser/Escritorio/singulardocs/sd-cert-issuer/pk\_issuer.txt' -c '/home/… --- ## [How to generate Verifiable Presentation with cert-issuer?](https://community.blockcerts.org/t/how-to-generate-verifiable-presentation-with-cert-issuer/3663)
**Author:** [@HarukiK](https://community.blockcerts.org/u/HarukiK)\ **Replies:** 9\ **Last updated:** [February 28, 2025, 5:03am UTC](https://community.blockcerts.org/t/how-to-generate-verifiable-presentation-with-cert-issuer/3663 "2025-02-28T05:03:12Z")
Hi! I’m a web3 enginner! I’m trying generate Verifiable Presentation with cert-issuer. I searched for the documentation but couldn’t find any information on how to issue a Verifiable Presentation, which is causing some… --- ## [Creating a verifiable certificate page for my students](https://community.blockcerts.org/t/creating-a-verifiable-certificate-page-for-my-students/3760)
**Author:** [@Wil2real](https://community.blockcerts.org/u/Wil2real)\ **Replies:** 0\ **Last updated:** [February 21, 2025, 10:08am UTC](https://community.blockcerts.org/t/creating-a-verifiable-certificate-page-for-my-students/3760 "2025-02-21T10:08:00Z")
I am new here, i want a to create an certificate and verification based system, where certificates can be verified. Any help --- ## [Why does blockcerts.org not working?](https://community.blockcerts.org/t/why-does-blockcerts-org-not-working/3751)
**Author:** [@abraham](https://community.blockcerts.org/u/abraham)\ **Replies:** 0\ **Last updated:** [February 15, 2025, 11:29pm UTC](https://community.blockcerts.org/t/why-does-blockcerts-org-not-working/3751 "2025-02-15T23:29:29Z")
Hi there ! Hope you’re doing well. I’m trying to open the Blockcerts official website (blockcerts.org) since many days, but it looks to not work. Surprisingly (and fortunately), the community site is working. Does anyo… --- ## [How to Securely Verify a Blockcert Credentials?](https://community.blockcerts.org/t/how-to-securely-verify-a-blockcert-credentials/3738)
**Author:** [@marcellosals](https://community.blockcerts.org/u/marcellosals)\ **Replies:** 2\ **Last updated:** [January 21, 2025, 12:48pm UTC](https://community.blockcerts.org/t/how-to-securely-verify-a-blockcert-credentials/3738 "2025-01-21T12:48:25Z")
Hello I am relatively new to using blockchain-based credentials and recently received my first Blockcert. While I understand the basics of how it works…, I want to ensure I am verifying these credentials in the most sec… --- ## [Can I use email for credentialSubject.id in blockcerts v3?](https://community.blockcerts.org/t/can-i-use-email-for-credentialsubject-id-in-blockcerts-v3/3728)
**Author:** [@Alise](https://community.blockcerts.org/u/Alise)\ **Replies:** 2\ **Last updated:** [January 18, 2025, 6:09pm UTC](https://community.blockcerts.org/t/can-i-use-email-for-credentialsubject-id-in-blockcerts-v3/3728 "2025-01-18T18:09:40Z")
I want to issue Blockcerts v3 certificates, but it is currently difficult for everyone in my organization to have a DID. Therefore, I am considering using each person’s email in the credentialSubject.id field. Are ther… --- ## [Am I understanding what really blockcert is about? Part 2](https://community.blockcerts.org/t/am-i-understanding-what-really-blockcert-is-about-part-2/3730)
**Author:** [@lodhabannerghattaroa](https://community.blockcerts.org/u/lodhabannerghattaroa)\ **Replies:** 1\ **Last updated:** [January 6, 2025, 11:11am UTC](https://community.blockcerts.org/t/am-i-understanding-what-really-blockcert-is-about-part-2/3730 "2025-01-06T11:11:23Z")
This is kind of a w3c Verified Credential (VC) but stored into a blockchain? After read the VC spec, I found (maybe im wrong) that the way you are aiming to dealing with the revoked certificates its indeed more decentra… --- ## [Not able to host certificate on eth testnet(sepolia) due to insufficient balance despite having balance 10x more than required](https://community.blockcerts.org/t/not-able-to-host-certificate-on-eth-testnet-sepolia-due-to-insufficient-balance-despite-having-balance-10x-more-than-required/3718)
**Author:** [@chirag](https://community.blockcerts.org/u/chirag)\ **Replies:** 0\ **Last updated:** [December 30, 2024, 2:10pm UTC](https://community.blockcerts.org/t/not-able-to-host-certificate-on-eth-testnet-sepolia-due-to-insufficient-balance-despite-having-balance-10x-more-than-required/3718 "2024-12-30T14:10:54Z")
WARNING - ‘Eth’ object has no attribute ‘getBalance’ WARNING - Missing/Invalid API KeyFile ERROR - “/home/ubuntu/blockchain-certificates/cert-issuer/venv/lib/python3.10/site-packages/cert\_issuer/blockchain\_handlers/eth… --- ## [Blockcerts wallet on Android does not add v3 certificates](https://community.blockcerts.org/t/blockcerts-wallet-on-android-does-not-add-v3-certificates/3643)
**Author:** [@OsoRuso](https://community.blockcerts.org/u/OsoRuso)\ **Replies:** 6\ **Last updated:** [October 21, 2024, 6:42am UTC](https://community.blockcerts.org/t/blockcerts-wallet-on-android-does-not-add-v3-certificates/3643 "2024-10-21T06:42:44Z")
Hello everyone I’m from Chile and I’m currently working on a project that uses version 3 of Blockcerts. I’ve been using the Blockcerts wallet on Android, but I’ve run into a problem when trying to add certificates issue… --- ## [How to add custom additional fields - BlockcertValidationError](https://community.blockcerts.org/t/how-to-add-custom-additional-fields-blockcertvalidationerror/276)
**Author:** [@uzu](https://community.blockcerts.org/u/uzu)\ **Replies:** 9\ **Last updated:** [October 14, 2024, 5:47am UTC](https://community.blockcerts.org/t/how-to-add-custom-additional-fields-blockcertvalidationerror/276 "2024-10-14T05:47:37Z")
Hello, I’m trying to create certificates containing custom additional fields. My cert-tools conf.ini contains the following line: additional\_global\_fields = {"fields": \[{"path": "$.badge.xyz\_custom\_field","value": "thi… --- ## [Best Practices for Implementing Blockcerts in Corporate Training Programs](https://community.blockcerts.org/t/best-practices-for-implementing-blockcerts-in-corporate-training-programs/3625)
**Author:** [@lilymurphy](https://community.blockcerts.org/u/lilymurphy)\ **Replies:** 1\ **Last updated:** [August 13, 2024, 7:26am UTC](https://community.blockcerts.org/t/best-practices-for-implementing-blockcerts-in-corporate-training-programs/3625 "2024-08-13T07:26:41Z")
Hi everyone! I’m exploring how Blockcerts can be leveraged in corporate training programs and I’m keen to hear from those who have experience in this area. I have been through these resources/articles What kind of suppo… --- ## [I want help on how to set up educational certification blocks](https://community.blockcerts.org/t/i-want-help-on-how-to-set-up-educational-certification-blocks/3607)
**Author:** [@Helen](https://community.blockcerts.org/u/Helen)\ **Replies:** 1\ **Last updated:** [August 13, 2024, 6:23am UTC](https://community.blockcerts.org/t/i-want-help-on-how-to-set-up-educational-certification-blocks/3607 "2024-08-13T06:23:35Z")
Hello everyone :wave: I am now exploring the use of block certificates for certifying in colleges and universities. Could anyone offer their experiences and ideas for ideal methods for setting up and handling a Blockcer… [Next page](https://community.blockcerts.org/latest.md?page=1)