Weirdly this problem has started for me now…updated shopify cli to the latest version too.
Request ID: 9a574d2d-e445-4308-817b-adc979ed6014-1781109109
shopify --version
@shopify/cli/4.1.0 wsl-x64 node-v24.16.0
I’m also starting to see this again! CLI boots up fine, then as soon as you hit the local host, it just errors out
Cli version 4.1.0
Request ID: a3f82979-bea1-4895-96c0-bf42fc3782dd-1781181630
Just started encountering this. Unfortunately the “logout/login” solution that worked for someone else is not working for me.
If you’re encountering the issue please try Josh’s snapshot to see if that fixes the issue Theme ID Mismatch - #19 by Josh-Shopify
Description
When running shopify theme dev, the local development server starts up normally. However, after serving the first few requests, the CLI throws a fatal Theme ID mismatch error and crashes the proxy session.
This issue persists on a completely clean machine environment across multiple package manager isolation attempts. It appears that the Shopify Storefront Renderer / Upstream APIs fail to carry forward the preview_theme_id context parameter on subsequent internal requests, causing the server-timing headers to drop back to the live theme ID, triggering the CLI safeguard crash.
Environment
- Operating System: macOS (Apple Silicon / arm64)
- Shopify CLI Version: 4.2.0 (Verified clean install via NVM global path)
- Node.js Version: v24.13.1
- Shell: zsh
- Package Manager Active Binary:
/Users/rafi/.nvm/versions/node/v24.13.1/bin/shopify
Steps to Reproduce
- Navigate to the root directory of a valid Shopify theme.
- Ensure you are authenticated to the store:
shopify theme dev --store marionskitchenshopau.myshopify.com - The local proxy loads correctly at
http://127.0.0.1:9292. - After 4 to 6 successful root requests (
GET 200 /), the server crashes instantly.
Actual Behavior
The CLI logs initial successful traffic and then yields this specific API conflict:
• 13:28:56 Request » GET 200 /
• 13:28:57 Request » GET 200 /
• 13:28:58 Request » GET 200 /
• 13:28:58 Request » GET 200 /
• 13:28:59 Request » GET 200 /
• 13:28:59 Request » GET 200 /
╭─ error ──────────────────────────────────────────────────────────────────────╮
│ │
│ Theme ID mismatch: expected 160488095993 but got 159878971641. │
│ Request ID: 20f71b0c-fc9b-4a14-a401-d7110adafeed-1781677739 │
│ URL: │
│ This is likely related to an issue in upstream Shopify APIs. │
│ Please try again in a few minutes and report this issue: │
│ [https://community.shopify.dev/c/shopify-cli-libraries/14](https://community.shopify.dev/c/shopify-cli-libraries/14) │
│ │
╰──────────────────────────────────────────────────────────────────────────────╯
Hey everyone,
Just a quick update for anyone still stuck on this! I reached out over on the Shopify CLI GitHub repository, and one of the Shopify contributors (@EvilGenius13) was able to apply a quick internal fix directly for my shop.
I just tested it on my end, and local development is working perfectly again—no more Theme ID mismatch errors or server crashes. 
If you are still experiencing this issue, I highly recommend chiming in on the GitHub thread so they can take a look at your specific store as well.
Here is the link to the relevant comment: https://github.com/Shopify/cli/issues/7344#issuecomment-4745474859
Hope this helps get you all unblocked!
We ran at this issue today too. No luck dealing with it. Shopify CLI v 4.5.0
Do you have a request ID you can share with us so we can investigate further?