This is happening for me too. Its weird to me because the Dawn theme is using es6, why would they change this?
Topic summary
Users are experiencing widespread minification failures on Shopify’s CDN, affecting hundreds of CSS and JavaScript files. The error messages indicate Shopify’s CDN is attempting to transform modern JavaScript (ES6) features—such as classes, const/let declarations, and object literal extensions—to ES5, but this transformation is not supported by their current tooling.
Key Technical Details:
- Error appears across multiple official Shopify themes (Dawn, Studio, Debut, Ride, Refresh)
- Affects files served through
/cdn/shop/t/104/assets/ - Started appearing around early July for some users
- Also triggers SEMrush warnings about unminified files and low text-to-HTML ratios
Proposed Solutions:
- One user created a GitHub repository with Gulp 4 + Babel pipeline to automatically minify and transpile ES6→ES5
- Shopify support suggested using Babel or manually converting ES6 to ES5
- Some developers recommend keeping ES6 and only minifying (not transpiling to ES5), as ES5 conversion often produces significantly larger file sizes that outweigh minification benefits
Current Status:
No official response from Shopify staff addressing why their CDN targets ES5 while themes use ES6. The discussion remains open with users seeking clarification on whether this impacts performance metrics (TTFB, FCP) and requesting official guidance.