shopify theme app extension breaks add to cart

The actual problem

A theme app extension JS error blocks ATC on mobile after a routine app update.

Do this

1. Console-check ATC on mobile after every app update.
2. Disable newest theme extensions until ATC works.
3. Pin working app versions during paid campaigns.
4. Keep a known-good theme preset to roll back.

Tools for this job

• Tillkiln

  Storefront/checkout trap detection

• Cashkiln checklist

  Pre-ads operator checks

Related intents

• shopify cart drawer checkout button not working
• shopify checkout app blocking place order button