RSS Block produces an error when trying to add a feed on plugin-enabled sites

[pauljacobson]

Quick summary

One of our customers reported that when they tried to add a RSS Block to their Single Posts template and subscribe to this feed, they saw an error in the block: https://www.ajplus.net/stories?format=rss

This is the error they saw:

The feed is valid, according to the W3C Feed Validator (see here). I initially thought this may be due to the feed being inactive (the last update was in June 2022).

I then tested this on a plugin-enabled site and experienced the same issue. I tested the block with the RSS feed for the WordPress.com Blog, and experienced the same error:

When I conducted the same test on a site on the WordPress.com Explorer plan, the block displayed the most recent posts as expected.

Steps to reproduce

1. In a plugin-enabled site, add a RSS Block and paste in a RSS feed;
2. Submit the feed;
3. See the error.

What you expected to happen

The RSS Block should display recent posts from valid, current feeds.

What actually happened

On plugin-enabled sites, the block fails to render a list of recent feed items.

Impact

Some (< 50%)

Available workarounds?

No but the platform is still usable

Platform (Simple and/or Atomic)

Atomic

Logs or notes

• I tested this with the Upsidedown and Twenty Twenty-Four themes on my plugin-enabled site.
• I tested this with the Erma theme on my WordPress.com Explorer plan site.
• Our customer's site uses the Spiel theme.
• I am using macOS 14.5 with Firefox Developer Edition v127.0b5
• Reported in 8191001-zen

[github-actions]

Support References

This comment is automatically generated. Please do not edit it.

• 8191001-zen

[mrfoxtalbot]

Thank you for the detailed report @pauljacobson!

This was directly related to #91097 (see more details in WordPress/gutenberg#61377) and has been fixed.

Updating to Gutenberg should fix the problem 18.4.1

[pauljacobson]

This was directly related to #91097 (see more details in WordPress/gutenberg#61377) and has been fixed.

Updating to Gutenberg should fix the problem 18.4.1

Ok, so we should advise the user to wait for 18.4.1 to be released? We manage these updates and I see my plugin-enabled site is on 18.4.0 currently.

[mrfoxtalbot]

Sorry, I jumped the gun too quickly. This seemed similar to the issue I mentioned above but I re-tested it and I can confirm the issue is still there on AT sites:

But works correctly on simple sites:

Kapture.2024-05-27.at.11.46.34.mp4

It also works fine on self-hosted:

Kapture.2024-05-27.at.11.52.37.mp4

I suspect this has to do with the URL formatting: ajplus.net/stories?format=rss. Something in the AT setup is not expecting the ?format=rss flag?

Could you help us confirm this, @Automattic/lego? Thank you

[taipeicoder]

@mrfoxtalbot is the issue consistently reproducible or only in some AT sites? I tried it with a couple of AT sites and they worked fine. The Lego team's experience with block is fairly low, but I'm happy to help troubleshooting and find folks that are more knowledgeable on this 🙂

[mrfoxtalbot]

Thank you very much for taking a look @taipeicoder. I am no longer able to reproduce this on any of my AT sites.

I am going to close it but please feel free to reopen if you can still replicate it, @pauljacobson.

Thank you!