# Forum not working after configuring CDN (ERR\_CERT\_COMMON\_NAME\_INVALID)
**URL:** https://meta.discourse.org/t/forum-not-working-after-configuring-cdn-err-cert-common-name-invalid/165100
**Category:** Support
**Tags:** cdn
**Created:** [September 23, 2020, 3:42pm UTC](https://meta.discourse.org/t/forum-not-working-after-configuring-cdn-err-cert-common-name-invalid/165100 "2020-09-23T15:42:35Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@Canapin](https://meta.discourse.org/u/Canapin)
#### Post date: [September 23, 2020, 3:42pm UTC](https://meta.discourse.org/t/forum-not-working-after-configuring-cdn-err-cert-common-name-invalid/165100/1 "2020-09-23T15:42:35Z")
Hi,
I configured stackpath CDN.
I configured my DNS with the provided info:
| TYPE | NAME | VALUE | TTL |
| --- | --- | --- | --- |
| A | @ | 151.139.128.10 | 300 |
| CNAME | www | [f5i4i8k5.stackpathcdn.com](http://f5i4i8k5.stackpathcdn.com/) | 300 |
I edited `app.yml` and rebuilt the app:
```plaintext
DISCOURSE_CDN_URL: https://www.unicyclist.com
```
But now the forum won’t load: `NET::ERR_CERT_COMMON_NAME_INVALID`
Any idea? ☹
edit: my CDN settings:
re edit: uuuh, now that’s a 503 error 🤔
---
### Author:  [@Falco](https://meta.discourse.org/u/Falco)
#### Post date: [September 23, 2020, 4:47pm UTC](https://meta.discourse.org/t/forum-not-working-after-configuring-cdn-err-cert-common-name-invalid/165100/2 "2020-09-23T16:47:52Z")
So what is the forum domain?
Shouldn’t you use
```plaintext
DISCOURSE_CDN_URL: https://f5i4i8k5.stackpathcdn.com
```
?
---
### Author:  [@Stephen](https://meta.discourse.org/u/Stephen)
#### Post date: [September 23, 2020, 7:19pm UTC](https://meta.discourse.org/t/forum-not-working-after-configuring-cdn-err-cert-common-name-invalid/165100/3 "2020-09-23T19:19:41Z")
Your CDN URL is your Site’s Edge Address at Stackpath, which as @falco noted is top-right in your screenshot.
You’ve specified the site URL as the CDN URL, leaving the site referring to… itself? Like some bizarre CDNipede 🐛
---
### Author:  [@Canapin](https://meta.discourse.org/u/Canapin)
#### Post date: [September 23, 2020, 9:11pm UTC](https://meta.discourse.org/t/forum-not-working-after-configuring-cdn-err-cert-common-name-invalid/165100/4 "2020-09-23T21:11:46Z")
Hi, thank you, I fixed my appl.yml. 👍
The error 503 is gone, but I’ve still the SSL issue 🤔
Here are the SSL settings in my stackpath panel, I don’t know if it’s of any usefulness:
```plaintext
This server couldn't prove that it's unicyclist.com;
its security certificate is from *.ssl.hwcdn.net.
```
---
### Author:  [@Falco](https://meta.discourse.org/u/Falco)
#### Post date: [September 23, 2020, 9:34pm UTC](https://meta.discourse.org/t/forum-not-working-after-configuring-cdn-err-cert-common-name-invalid/165100/5 "2020-09-23T21:34:30Z")
So you have a VPS running on `151.139.128.10`, a DNS entry for `unicyclist.com` of type `A` pointing to `151.139.128.10` and your app.yml hostname is set to `unicyclist.com` ?
---
### Author:  [@RGJ](https://meta.discourse.org/u/RGJ)
#### Post date: [September 23, 2020, 9:41pm UTC](https://meta.discourse.org/t/forum-not-working-after-configuring-cdn-err-cert-common-name-invalid/165100/6 "2020-09-23T21:41:11Z")
So you will need to “create an additional certificate to use with custom Delivery Domains” using that blue button in the middle.
---
### Author:  [@Canapin](https://meta.discourse.org/u/Canapin)
#### Post date: [September 23, 2020, 9:44pm UTC](https://meta.discourse.org/t/forum-not-working-after-configuring-cdn-err-cert-common-name-invalid/165100/7 "2020-09-23T21:44:16Z")
Well, I’m a bit lost (and reply precisely to your question at the end of the message)
I followed this #howto:
[https://meta.discourse.org/t/enable-a-cdn-for-your-discourse/14857](https://meta.discourse.org/t/enable-a-cdn-for-your-discourse/14857)
> 1. The **CNAME** , which is the “friendly” name for your CDN that you’ll set up in your DNS, e.g. `discourse-cdn.example.com`
> 2. The **CDN URL** , which is the “unfriendly” name for where the cached CDN assets will be coming from via the CDN’s worldwide network of distributed servers. It will look like `637763234.cdn-provider.com`
Stackpath told me to add this in my DNS (the screenshot is from my stackpath configuration steps):
The CNAME entry being www, I assumed that the “friendly” name for my CDN would be [www.unicyclist.com](http://www.unicyclist.com).
Then, still following the #howto where the “friendly” name is added to the app.yml:
> Uncomment the CDN line in your `app.yml` and update it with the CNAME you just set up in your DNS:
>
> ```plaintext
> ## the origin pull CDN address for this Discourse instance
> DISCOURSE_CDN_URL: //discourse-cdn.example.com
>
> ```
I did the same and I set DISCOURSE\_CDN\_URL to [www.uncyclist.com](http://www.uncyclist.com)
So I don’t quite understand why I should set the “unfriendly” name in my app.yml when the #howto tell me the opposite.
As for the IP and domains:
My VPS IP is `95.217.21.71`.
The A entry that I added following stackpath’s configuration steps is their own IP (as I understand it).
My app.yml hostname is `unicyclist.com`.
> [@RGJ](#):
>
> So you will need to “create an additional certificate to use with custom Delivery Domains” using that blue button in the middle.
Oh, I’ll have a look at this!
Yup: that was that. Thanks guys!
---
### Author:  [@system](https://meta.discourse.org/u/system)
#### Post date: [October 23, 2020, 9:48pm UTC](https://meta.discourse.org/t/forum-not-working-after-configuring-cdn-err-cert-common-name-invalid/165100/8 "2020-10-23T21:48:48Z")
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