`TypeError: Load failed` causing crashes on WebKit browsers

Hey there,

Nice to meet some of you at the DotDev event :).

We've built a storefront for an enterprise client that I'm super happy with, but there's an issue that appears in our logs that I can't reproduce. It crashes the frontend, showing an error boundary in 0.79% of sessions, which is way too much at our scale.

I have attached the production logs. Here's what I've found:

• Only in WebKit browsers
• A fetch request to a .data fetch request is logged with statusCode=0
• Server-side logs for the same sessions return successfully with statusCode=200
• Error boundary shows, crashing the page

I hope you can help us understand why a successful server response isn't reaching the user. And is there a way to handle this more gracefully?

I can't share our codebase publicly, but I'd be happy to walk you through it. It's very close to the Hydrogen example. We do have a Cloudflare worker for traffic routing in front of Oxygen, but this doesn't cause any (other?) issues.

Kind regards,

Wiebe

Session logs

The logs include a status code of 500 for the client-side error boundary because we labeled it that way in our frontend code. It's not an actual 500. Confusing, I know.

session-4afd71d9-pdp-predictive.csv
session-9d7b0c22-login-navigation-2.csv
session-70e0a899-cart-navigation.csv
session-820a2263-suits-predictive-search.csv
session-3884a2e6-stores-navigation.csv
session-4034dfd8-plp-predictive.csv
session-de363bc6-home-predictive.csv
session-df00ab4f-search-predictive.csv
session-f3055940-login-navigation.csv
session-ffc52bc0-home-search-predictive.csv

Which package or tool is having this issue?

Hydrogen

What version of that package or tool are you using?

2026.4.2

What version of React Router 7 are you using?

7.15.1

Start by comparing the attached session CSV logs, focusing on WebKit sessions where the .data fetch has statusCode=0 while server logs show 200. Reproduce with Hydrogen 2026.4.2 and React Router 7.15.1 in a WebKit browser, then determine the cause and verify that the error boundary handles the failed fetch without crashing the page.