# RUM agent facing Cert Authority Invalid in Browser Tools

**URL:** <https://discuss.elastic.co/t/rum-agent-facing-cert-authority-invalid-in-browser-tools/346099>\
**Category:** APM\
**Tags:** rum\
**Created:** [October 31, 2023, 8:59am UTC](https://discuss.elastic.co/t/rum-agent-facing-cert-authority-invalid-in-browser-tools/346099 "2023-10-31T08:59:07Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![Ong](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/ong/32/40766_2.png) [@Ong](https://discuss.elastic.co/u/Ong)\
**Post date:** [October 31, 2023, 8:59am UTC](https://discuss.elastic.co/t/rum-agent-facing-cert-authority-invalid-in-browser-tools/346099/1 "2023-10-31T08:59:07Z")

</div>

I set up RUM agent for a React application and am facing ERR\_CERT\_AUTHORITY\_INVALID errors from Developer Tools in the Edge browser. I have set up a self signed cert on my Windows desktop but the error still appears.

The RUM initialisation code is:

```auto
import {init as initApm} from '@elastic/apm-rum';

var apm = initApm({
  serviceName: 'web',
  serviceUrl: 'https://xxx.apm.ece.dev.org:9243',
  serviceVersion: '1.0',
  logLevel: 'error',
  environment: 'dev'
)};

```

![cert authority](https://us1.discourse-cdn.com/elastic/original/3X/d/d/dd271428f36ade303dd6a4bf958802413d6d4146.png)

When I removed the 9243 port from serviceUrl, the error became ERR\_CERT\_COMMON\_NAME\_INVALID.

What can be done to solve this cert error?

**Kibana version** : 8.5

**Elasticsearch version** : 8.5

**APM Server version** : 8.5

**APM Agent language and version** : RUM 5.14.0

**Browser version** : Edge

**Is there anything special in your setup?** There is a Nginx in front of the ECE machines

**Errors in browser console (if relevant)**: ERR\_CERT\_AUTHORITY\_INVALID

**Provide logs and/or server output (if relevant)**:

---

<div class="post-metadata">

**Author:** ![Alberto\_Delgado](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/alberto_delgado/32/98488_2.png) [@Alberto\_Delgado](https://discuss.elastic.co/u/Alberto_Delgado)\
**Post date:** [October 31, 2023, 9:44am UTC](https://discuss.elastic.co/t/rum-agent-facing-cert-authority-invalid-in-browser-tools/346099/2 "2023-10-31T09:44:06Z")

</div>

Hi @Ong,

Thanks for reaching out!

I've been checking your case, and the error you have is not related to the RUM product. The error is taking place because the browser (in this case Edge) doesn't trust the self-signed certificate.

I'm going to share with you two links that highlight how to deal with certificates and why these errors happen.

An excerpt from one of the links:

_"One possible cause of this error is that a self-signed certificate is installed on the server. Self-signed certificates aren't trusted by browsers because they are generated by your server, not by a CA. ..."_

1. [https://www.digicert.com/kb/ssl-support/certificate-not-trusted-error.htm](https://www.digicert.com/kb/ssl-support/certificate-not-trusted-error.htm)
2. [Issuing valid certificates for LAN-only websites | Rafael Cavalcanti](https://rafaelc.org/posts/issuing-valid-certificates-for-lan-only-websites/)

Cheers,  
Alberto

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [November 28, 2023, 9:44am UTC](https://discuss.elastic.co/t/rum-agent-facing-cert-authority-invalid-in-browser-tools/346099/3 "2023-11-28T09:44:56Z")

</div>

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