Why can't I add a featured product to cart in Effortless Theme?

Technical Q&A
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Topic summary

A user is experiencing an error when attempting to add a featured product to the cart on their homepage using the Effortless Theme.

The error message appears to be displayed in reverse text, but when corrected reads: “Missing or Invalid Parameter: Required parameter missing or invalid: items” followed by “What can I do? - Return to the previous page. Request ID: [alphanumeric string]”

The issue cannot be resolved through the theme settings alone and requires coding intervention. The user is seeking help to fix the underlying code causing this cart functionality problem.

Summarized with AI on November 14. AI used: claude-sonnet-4-5-20250929.
1

I have a featured product on my main page - Effortless Theme, and when trying to add to cart it shows an error message transcribed below.

Can someone help with coding??? Apparently there’s nothing I can do through the theme settings…

Below is the message I get:

Parameter Missing or Invalid: Required parameter missing or invalid: items

What can I do?

  • Return to the previous page.

Request ID: 66105d41-8d9b-4d83-8cf9-d632baeb1622"