# Getting Cloudflare 521 Error After Upgrade to 3.5.0.beta8-dev

**URL:** <https://meta.discourse.org/t/getting-cloudflare-521-error-after-upgrade-to-3-5-0-beta8-dev/375963>\
**Category:** Product Support\
**Tags:** cloudflare\
**Created:** [July 26, 2025, 6:22pm UTC](https://meta.discourse.org/t/getting-cloudflare-521-error-after-upgrade-to-3-5-0-beta8-dev/375963 "2025-07-26T18:22:08Z")\
**Posts on this page:** 1\
**Showing post:** 5

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**Author:** ![LW2333](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/lw2333/32/511642_2.png) [@LW2333](https://meta.discourse.org/u/LW2333)\
**Post date:** [July 27, 2025, 2:43am UTC](https://meta.discourse.org/t/getting-cloudflare-521-error-after-upgrade-to-3-5-0-beta8-dev/375963/5 "2025-07-27T02:43:40Z")

</div>

Cloudflare now privide Certificates that valid for up to 15 years, mine is still within the valid period.

 ![image](https://global.discourse-cdn.com/meta/original/4X/1/f/4/1f40245b3fc604d2a81ef0f559bb1c300f8718bf.png)

That said, just to be sure, I also tried generating a new certificate and replaced the existing one, but I still got the same problem.

If I want to switch back to the default setup using Let’s Encrypt,  
is it enough to simply:

1. Uncomment this line in `app.yml`:

```plaintext
- "templates/web.letsencrypt.ssl.template.yml"

```

1. And set Cloudflare’s SSL mode to Full?

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