Add to Cart button won't work after I change variant

Shopify Discussion

Topic summary

A Shopify store owner reports that their Add to Cart button becomes unclickable (grays out) after switching product variants (color or size). The button only works for the first variant selection and requires a page refresh to function again.

Diagnosis:

  • Multiple responders identify this as a JavaScript conflict issue
  • Console errors appear intermittently
  • A specific error related to ‘VariantChange’ in global.js was identified (screenshot provided)

Suggested solutions:

  • Revert recent changes made to global.js or product template
  • Review recently installed/uninstalled apps that may cause conflicts
  • Reference a similar resolved case in another Shopify community thread

Current status:

  • The original poster lacks coding experience and requested assistance
  • Two developers offered paid services and requested collaborator access to fix the issue
  • Discussion remains open, awaiting the store owner to share collaborator credentials for direct troubleshooting
Summarized with AI on November 3. AI used: claude-sonnet-4-5-20250929.
1

Hello, I’ve searched through a lot of similar questions about this and none have seemed to fix the problem

I have got a Problem with my Add to cart button. If i switch the variant (colour or size) of the Product, the add to cart button gets grey and i cannot click it anymore. Just After refreshing the site i can click on add to cart but only for the firsst variant. If i press another variant, i cant click it again.

Website link - thevaultcompany.ca

2

Hello @VaultCo ,

Sometimes it’s working, sometimes it’s not.

And same with errors sometimes it throws errors in console sometimes it’s not.

Actual case is a JS conflict.
You need to revert the change you did in global.js or product template recently. Also check the apps which you installed/uninstalled recently.
btw if nothing works then you need to go with a developer to fix it.

Regards
Guleria

3

Hey @VaultCo check out the marked reply here https://community.shopify.com/post/2023408

Just as I thought, you might have to remove some code due to the switch.

4

Hi @Yabiola , I understand this, but unfortunately, I do not have coding experience. Would you be willing to help me out with this?

5

Hi @Bundler-Manuel , I understand this, but unfortunately, I do not have coding experience. Would you be willing to help me out with this?

6

Hi @Guleria , I understand this, but unfortunately, I do not have coding experience. Would you be willing to help me out with this?

7

@VaultCo Yes sure, I provide services. Please drop an email to discus it further.

You can find email in signature below.

Regard
Guleria

8

How do we start? Do you want me to share Collaborator link so that you can check our theme code?

9

Well, I could clearly see there is an error related to VariantChange in your global.js. I’m sure we’ll be able to fix it. Attaching the screenshot for your reference.

TheUntechnickle_0-1735529132753.png
TheUntechnickle_0-1735529132753.png2940×1656 576 KB

Please share your collaborator code so that we can send you a store access request and fix this.

Thanks,
Shubham | Untechnickle