Shopify Theme Editor Blank Screen + WebSocket Failure (trycloudflare.com/extensions)

Online Store and Theme Development
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1

Short description of issue

Shopify Theme Editor shows a blank screen during local theme development. Storefront preview works correctly, but Theme Editor fails due to a websocket connection error related to trycloudflare.com/extensions.

Link to Shopify Store

Reproduction steps

shopify theme dev -s https://kaijus-parts.myshopify.com

Open the generated Theme Editor URL:
/admin/themes/{theme_id}/editor?hr=9292

Theme Editor loads as a blank screen.

Browser console shows:
WebSocket connection to ‘wss://*.trycloudflare.com/extensions’ failed

The storefront preview at http://127.0.0.1:9292 works correctly.

Additional info

Shopify CLI version: 4.2.0
Node.js version: 24.15.0
OS: Windows 10
Browser: Chrome

The storefront preview at http://127.0.0.1:9292 works correctly.

Tried:

Clearing cache/cookies
Incognito mode
Disabling browser extensions
shopify auth logout and login
Removing .shopify folder
Running without --live-reload full-page
Using --host 127.0.0.1

Issue only affects Theme Editor websocket connection.

What type of topic is this

Bug report

Upload screenshot(s) of issue

theme admin error 2.png
theme admin error 2.png1918×969 47.9 KB
theme admin error 1.png
theme admin error 1.png1918×967 55.8 KB

2

Hi @SUDHAGAR_G, thanks for the report! We’ve received a couple more via our Support teams and I have been able to replicate.

From my testing this only occurs on Partner Dev stores and not Plus Dev stores, and isn’t specific to the latest CLI version - I replicated on 3.88.0

We’ve raised this with the responsible team internally and I’ll follow up here once I have additional info to share - thanks again for flagging!

4

Thanks for the update and for confirming the issue on your side as well.

That aligns with what I was seeing during testing. Good to know it’s reproducible across multiple CLI versions and appears to be specific to Partner Dev stores rather than the local environment or theme code itself.

I appreciate the investigation and escalation to the responsible team. Please let me know if you need any additional logs, reproduction details, or testing from my side.

6

Hi @SUDHAGAR_G, appreciate your patience on this! For the sake of clarity we’re going to consolidate communications on this thread since its older and has more activity. I’ll post any updates there instead.