AMP Validation Issue: Disallowed attribute or attribute value present in HTML

Thanks for opening a support topic. From checking your site with the AMP validator I can see the same error, which can indeed be resolved be removing the space before the loading value, see below, or this video:

Why is there a space in loading=” lazy”?

Great question. As I don’t see the space included on your non AMP URLs can you share any plugin or theme feature which is adding this attribute? You could use the Health Check & Troubleshooting plugin to rule out a multi plugin conflict, and see does the same issue exist starting with only the AMP plugin. We have a guide on the plugin website. Alternatively let me know of the plugin or theme feature you’re using and we can check this from out side.

In troubleshooting mode, the issue is gone.

However even with all plugins enabled in troubleshooting mode, the issue is still resolved.

What does this mean?

Here is a list of my plugins:
Content Aware Sidebars – Disable
Advanced noCaptcha & invisible Captcha – Disable
Akismet Anti-Spam – Disable
AMP for GeneratePress – Disable
AMP – Disable
Show 52 remaining plugins
The SEO Framework – Disable
Ban Hammer – Disable
bbP private groups – Disable
bbp style pack – Disable
bbPress – Disable
Blog2Social: Social Media Auto Post & Scheduler – Disable
Broken Link Checker – Disable
Classic Widgets – Disable
Co-Authors Plus – Disable
Code Snippets – Disable
Content Control – Disable
Yoast Duplicate Post – Disable
Fanciest Author Box – Disable
Fixed TOC – Disable
FluentCRM – Marketing Automation For WordPress – Disable
FluentSMTP – Disable
FluentCRM Pro – Disable
Fluent Forms – Disable
Fluent Forms Pro Add On Pack – Disable
Font Awesome – Disable
GenerateBlocks – Disable
Site Kit by Google – Disable
GP Premium – Disable
Health Check & Troubleshooting – Disable
Hierarchical HTML Sitemap – Disable
Imagify – Disable
Lightweight Social Icons – Disable
Media Library Organizer – Disable
Pods Alternative Cache – Disable
Pods – Custom Content Types and Fields – Disable
Pre-Publish Checklist – Disable
Reading Time WP – Disable
Schema & Structured Data for WP & AMP – Disable
Scriptless Social Sharing – Disable
Simple CSS – Disable
Swift Performance Lite – Disable
TablePress Extension: DataTables FixedColumns – Disable
TablePress Extension: Responsive Tables – Disable
TablePress Extension: Table Auto Update – Disable
TablePress – Disable
The SEO Framework – Extension Manager – Disable
ThirstyAffiliates – Disable
UpdraftPlus – Backup/Restore – Disable
Username Changer – Disable
Widget CSS Classes – Disable
Wordfence Security – Disable
WP Featherlight – Disable
WP Grid Builder – Disable
WP Ultimate CSV Importer – Custom Fields Import – Disable
WP Post Series – Disable
WordPress RSS Feed Retriever – Disable
WP Show Posts – Disable`

Oh and I’m still on the theme I normally have active.

Nice troubleshooting @reedus33!

Now that you’ve confirmed the error no longer exists with just the AMP plugin while in troubleshooting mode please enable your other plugins one by one, before checking the validation status on that same URL you referenced each time. You can use the plugins admin toolbar or the AMP validator Chrome extension to check the status.

As soon as you encounter the error you’ll know which plugin is causing this validation error. It may be a particular configuration which we can check should we determine the conflict. As you have a large number of plugins actives please start with the plugin that impact your markup output, such as the below:
– WP Featherlight
– Swift Performance Lite
– The SEO Framework

Let me know how you get on with the above.

Hi James

As I said, I did this. Even after enabling all plugins one by one in troubleshooting mode, the issue did not present.

In fact, when I am logged into wordpress, there is no space in ” lazy”, its only on the public facing site.

Very strange…

Hmm so I think it might have something to do with WordPress update now including native lazy loading.

I enabled lazy loading in my caching plugin and the issue seems to be resolved…

Hi @reedus33,

Thanks for the update. WordPress does lazy load images by default as of version 5.5, for images that have defined widths and heights. Where there was the space included I can’t be sure.

I enabled lazy loading in my caching plugin and the issue seems to be resolved…

Was this your Swift plugin, and if you deactivate the same plugin does the same error appear?

As we didn’t receive a response I’ll mark this as resolved. Feel free to open a new support topic if you require any further assistance.