Can't change quantity in cart or delete items

Technical Q&A

Topic summary

A store owner is experiencing critical cart functionality issues after updating their product-form.js code to fix an “add to cart” button problem. While the add-to-cart function now works, two new errors have emerged:

Current Problems:

  • Unable to change item quantities in cart
  • Cannot delete items from cart
  • Error messages appear when attempting these actions (screenshot provided)

Technical Context:

  • Theme: Spotlight version 11.0.0
  • Language: German
  • Store URL: christopherherrmann.com
  • Previous fix involved replacing entire product-form.js code based on forum suggestion

Status: Unresolved and marked as urgent. One developer responded offering assistance, mentioning they solved a similar issue in a different theme (Shrine) where cart updates required page refresh. The issue appears JavaScript-related and may require theme-specific debugging.

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

Hi there,

a few months ago I started to help a friend updating and improving his Store.

Just some optical changes, a little bit of code, but nothing severe.

Last week he messaged me, that he had his first customer but also this customer discovered that she couldn’t put items in cart and could only buy via PayPal.

After searching here I found a post were they suggested to exchange the whole code in the product-form.js and it worked, the “add to cart” button is now working probably.

But now I’m getting two errors when I try to change the quantity or want to delete the articles in the cart:

floh_media_0-1738756425114.png
floh_media_0-1738756425114.png1113×292 8.14 KB

I already searched and couldn’t find anything on that problem. I didn’t change anything directing the buying process, so I definitely don’t know where that error came from.

The store is https://www.christopherherrmann.com/

The used theme is Spotlight, Version 11.0.0, but I don’t know where it came from.

The language is currently only German, sorry for that.

Thank you very much in advance for helping! This is very urgent and drastic…

Greetings floh

2

I am not sure about this as different themes have different code bases but I was able to come up with a solution for shrine theme where the user could not update or remove items from the cart drawer dynamically, so it did remove or update but needed a page refresh.

Would definitely love to take a look at this. Please reach out via personal links below for a convenient conversation and collaboration.

Best

Shadab