Seeking Help: Persistent TypeError in New Shopify Remix Template (July 2025) #1117
Description
Hello everyone,
I'm developing a Shopify app and have hit a persistent blocker that I can't solve. I would be extremely grateful for any help or insight from the community.
I'm using the official Shopify App template for Remix with TypeScript, scaffolded using the latest version of npm init @shopify/app@latest. After setting up the project and adding my application logic, I'm consistently running into an error that completely blocks the app from loading any authenticated route.
The Error:
TypeError: (0 , vite_ssr_import_3.addDocumentResponseHeaders) is not a function
The stack trace consistently points to the app/entry.server.tsx file as the origin of the crash.
What I've Already Tried (Without Success):
I have spent several days trying to debug this issue. My troubleshooting process has included:
Complete Dependency Rebuild: Deleting node_modules and lockfiles (package-lock.json, yarn.lock), clearing the cache (npm cache clean --force), and reinstalling everything from scratch using both npm and yarn.
Scaffolding Multiple New Projects: I have created three separate projects from scratch using the CLI to rule out an initial configuration error. The issue appears in every new project.
Configuration Validation: I have meticulously checked and validated the .env, package.json, and shopify.app.toml files to ensure all API keys and scopes are correct.
API Permissions: I have successfully requested and been granted "Protected Customer Data Access" for the app in the Shopify Partner Dashboard and have fully uninstalled and reinstalled the app on my development store multiple times to refresh the access token.
Applying Patches & Workarounds: I have tried applying community-suggested patches for entry.server.tsx from older forum posts and have also attempted to bypass the issue by replacing Shopify's ErrorBoundary and removing the headers export in app.tsx. None of these attempts have resolved the underlying TypeError.
The error seems to be a fundamental bug or a critical incompatibility within the version of the @shopify/shopify-app-remix library that is installed by default.
My Question:
Has anyone else encountered this specific bug with recent versions of the Remix template (as of July 2025)? Is this a known issue, and are there any solutions or workarounds I haven't tried?
I'm at a standstill and truly want to move this project forward. I appreciate any help, ideas, or guidance you can offer.
Thank you!