Unable to access AIO site due to expired Let's Encrypt certificate

ℹ️ Support
1
  • Nextcloud Server version: NextCloud 34.0.1 (Hub 26 Spring)
  • Operating system and version: Linux Mint
  • Web server and version: Standard web server for NextCloud AIO
  • Reverse proxy and version: Standard NextCloud AIO setup. (I didn’t add any other proxy.)
  • PHP version: 8.3.32
  • Is this the first time you’ve seen this error? Yes
  • When did this problem seem to first start? July 27 or so, when the certificate expired
  • Installation method: AIO
  • Are you using Cloudflare, mod_security, or similar? No

Summary of the issue you are facing:

Hi everyone, when attempting to access my locally-hosted NextCloud AIO site these past few days, I’ve received an error related to an expired certificate (net::ERR_CERT_DATE_INVALID within Brave). My Let’s Encrypt certificate was issued on June 12, 2026, but expired on July 27.

I tried restarting the computer on which NextCloud is hosted to see if this would fix the issue, but it unfortunately did not.

I had assumed that Let’s Encrypt certificates would automatically get refreshed for AIO setups, but pehaps this isn’t the case? Is there anything I need to do to manually refresh the certificate?

Thanks in advance for your help!

Steps to replicate it (hint: details matter!):

The issue occurs when I attempt to access my public NextCloud domain on any web browser.

Log entries: I didn’t see any error messages that appeared directly relevant to this expired encryption.

Web Browser

I didn’t see any relevant messages from the Console or Network tabs, but here’s what I saw using the Brave browser when attempting to access my site:


Your connection is not private
Attackers might be trying to steal your information from [my public NextCloud URL] (for example, passwords, messages, or credit cards). Learn more about this warning

net::ERR_CERT_DATE_INVALID

[my public NextCloud URL] normally uses encryption to protect your information. When Brave tried to connect to [my public NextCloud URL] this time, the website sent back unusual and incorrect credentials. This may happen when an attacker is trying to pretend to be [my public NextCloud URL], or a Wi-Fi sign-in screen has interrupted the connection. Your information is still secure because Brave stopped the connection before any data was exchanged.

You cannot visit [my public NextCloud URL] right now because the website uses HSTS. Network errors and attacks are usually temporary, so this page will probably work later.
2

We can’t help you if you’re unwilling to fill out the basics of the support template.

4

Sorry about that. I’ve now filled out the basics. If there’s any more information you might need, just let me know.

5

From outside your network or from locally on your network?

Is your Nextcloud instance reachable from the public Internet or firewalled off?

Maybe also post your Compose file, which might turn up something else.

6

Thanks for responding! It’s reachable on the public internet. This error occurs both within my local Wi-Fi and on a separate network.

My Docker compose file is the standard AIO setup, except that I added a small snippet (found on the AIO GitHub page, I believe) to enable external storage. I can still post the full command when I get back to the server, though.

I also confirmed that Port 80 is accessible from the public internet.

7

Happily enough, the site is now accessible again! A new Let’s Encrypt got issued automatically around 3 AM this morning; it is valid until September 20. (I’ll see if the issue reoccurs on or after that date, though.)