(URGENT) Why does my website freeze when adding products to cart?

Technical Q&A

Topic summary

A website owner reports critical cart functionality issues causing sales drops: pages freeze after clicking “Add to Cart” (requiring users to click elsewhere to unlock scrolling), and a false “out of stock” error appears at checkout despite items remaining in cart.

Current Status:

  • Issue confirmed by one responder who reproduced the freezing behavior on a specific product page
  • Another user reports no issues, suggesting inconsistent occurrence

Proposed Solutions:

For Page Freezing:

  • Check browser console for JavaScript errors in product-form.js or theme.js
  • Look for modal/overlay elements not properly closing after AJAX cart events
  • Temporarily disable third-party apps (sticky cart, upsell, popup tools) to identify conflicts
  • Test with a backup/duplicate theme to isolate code issues

For False Stock Errors:

  • Verify inventory tracking settings and variant configurations in Shopify admin
  • Check for cart scripts or inventory management apps causing conflicts
  • Disable checkout-interfering apps temporarily

General Troubleshooting:

  • Clear cache and cookies
  • Test in incognito/different browsers
  • One responder offered direct code review via collaborator access

No resolution reached yet; investigation ongoing.

Summarized with AI on October 29. AI used: claude-sonnet-4-5-20250929.
1

Hi everyone! I am having problems with both the desktop and mobile version of my website - visit https://gellae.com.au/

My website is currently glitching with the Add to Cart button on my product pages that is causing the page to freeze after the customer clicks the Add to Cart button. I can’t scroll up or down unless the customer clicks something else that is clickable, then it unlocks.

Also, when I click checkout, a pop up with “out of stock, some items are no longer available and removed from your cart” (screenshot attached) appears where I can click Continue Checkout" but nothing has been removed from cart and I can check out.

We have seen a massive drop in sales, which is very frustrating.

Any suggestions on how to fix this? I am not a skilled coder but I am able to read through the code if someone could direct me on where to look.

Thanks guys!

SereneGellae_0-1744778815855.png
SereneGellae_0-1744778815855.png274×583 30.2 KB

1 Like
2

Hey @SereneGellae

I just checked your website and for me everything is working completely fine, is this issue happening on a specific product page? Let me know.

Best Regards,

Moeed

3

That’s good to know that this does not affect everyone. Try adding this product to cart? https://gellae.com.au/products/pink-hailey-glazed-donut-diy-semicured-gel-nail-sticker-kit

1 Like
4

Hi @SereneGellae ,

According to your message, there are two main issues:

Issue 1: “Add to Cart” Freezes Page Until Another Element is Clicked
Diagnosis: This is typically a JavaScript issue caused by:

An unhandled event in your theme’s product-form.js or theme.js
A modal or overlay that remains active but invisible after the “Add to Cart” event
Shopify AJAX cart errors or a third-party app script causing conflicts

Steps to Fix:

Check Console Errors (on Chrome DevTools):
Right-click your page → Inspect → Console tab
Try adding a product to cart and see what errors show up

Look in product-form.js or theme.js:
Find the function handling the “Add to Cart” event
Make sure the function finishes properly and doesn’t leave a modal or overlay open
Common issue: loading overlays not being hidden after AJAX call completes

Temporarily disable third-party apps:
Apps like sticky cart, upsell, or popup cart might cause interference
Disable apps one by one and test the add to cart function

Test on a Backup Theme:
Duplicate your current theme (Online Store > Themes > Actions > Duplicate)
Try using Shopify’s Dawn theme and test Add to Cart functionality there
If it works fine, your current theme has a code issue

Issue 2: “Out of Stock” Message at Checkout but Nothing Is Actually Removed
Diagnosis: This is usually due to:
Theme or app cache not syncing with inventory
Delayed updates to inventory levels via Shopify’s backend
Products having multiple variants with inventory tracking improperly set

Steps to Fix:

Check Inventory Settings:
Go to your Shopify Admin → Products → Click a product → Check “Track quantity” and “Continue selling when out of stock”
Ensure all variants have inventory assigned

Check Draft Orders or Cart Scripts:
If you’re using Shopify Plus, a script might incorrectly trigger this message
Otherwise, check for cart-related scripts or third-party apps that modify cart behavior

Disable Apps that Interfere with Checkout:
Apps that manage inventory (pre-orders, back-in-stock, etc.) can trigger false out-of-stock errors
Disable them temporarily to isolate the issue

Hope this will help. Let me know if you need more help.

Regards,

5

Hey @SereneGellae

I can see that after adding the product to the cart and closing the cart drawer I’m unable to scroll away and can only click. On the front end code everything looks fine for me. The issue could be occurring either because of a third party app or some invalid JS code in your theme files.

If you can share your collaborator request code in my private messages then I’d be happy to have a detailed look at it and help in solving this problem.

Best Regards,

Moeed

6

Hello there Serene @SereneGellae If you haven’t cleared the cache cookies in your store yet you should try that. Also, try loading it on a different or incognito browser to see if the issue persists.