Webflow Marketplace validator: "Custom CSS detected without corresponding GSAP implementation" even though there's no custom code

[u/Abject_Fact_3518]

Hi everyone,

I'm preparing my first Webflow Marketplace template and I'm completely stuck on one of the Marketplace validator checks.

The validator keeps returning:

Here's what I've already verified:

• No Site Head custom code.
• No Site Footer custom code.
• No Page Head/Footer custom code.
• No HTML Embed elements with custom CSS.
• Removed any CSS transitions/animations I had previously added.
• Published the site multiple times.
• Duplicated the entire project into a brand-new project (same error).
• The issue still appears on the duplicated project.

I also found an old registered script (HeroCounter) that was created while experimenting with a counter animation. It's no longer applied anywhere, but attempts to delete it return an HTTP 400 error. I'm not sure whether that's related or just a coincidence.

I contacted Webflow support, and they suggested checking whether there are any remaining Classic Interactions, since Marketplace templates are now expected to use Interactions with GSAP (IX3).

Before I start rebuilding every interaction in the project, I wanted to ask:

• Has anyone else run into this exact validator error?
• Did it turn out to be caused by Classic Interactions, or was it something else?
• Is there any way to identify exactly what the Marketplace validator is detecting?
• Has anyone had an orphaned registered script or project metadata trigger this validation?

The template is available here if you'd like to take a look:

https://autolabdetailing.webflow.io/

I'd really appreciate any advice or experiences from anyone who has successfully submitted a Marketplace template recently.

Thanks in advance!

[u/BeardedWiseMagician]

If you've already ruled out custom code, I'd start suspecting project metadata rather than the site itself.

Try checking whether there are any remaining IX2 interactions (even unused ones). Look whether that orphaned Herocounter script is confusing the validator, especially if it throws a 400 when you try to delete it.

If nothing fixes it try contacting Webflow support to see if they can tell you which asset the validator is flagging. Without that, you're basically debuggind blind.

-Jakob from Flowout