# 401 Unauthorized - "Error creating public key from user certificate" (code -7) on sandbox

**URL:** <https://community.fireblocks.com/t/401-unauthorized-error-creating-public-key-from-user-certificate-code-7-on-sandbox/3023>\
**Category:** Developer Discussion\
**Created:** [November 26, 2025, 9:52am UTC](https://community.fireblocks.com/t/401-unauthorized-error-creating-public-key-from-user-certificate-code-7-on-sandbox/3023 "2025-11-26T09:52:03Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![DavidSwapped](https://avatars.discourse-cdn.com/v4/letter/d/a3d4f5/32.png) [@DavidSwapped](https://community.fireblocks.com/u/DavidSwapped)\
**Post date:** [November 26, 2025, 9:52am UTC](https://community.fireblocks.com/t/401-unauthorized-error-creating-public-key-from-user-certificate-code-7-on-sandbox/3023/1 "2025-11-26T09:52:03Z")

</div>

Getting this error when calling `POST /v1/transactions` on sandbox:

```auto
{ "message": "Unauthorized: Error creating public key from user certificate", "code": -7 }
Setup:

```

Can anyone help why this is happening? Nothing changed on our end.