422 Error after customer registration with Extension Block

Retired Boards Appdev Extensions

Topic summary

A user encounters a 422 Unprocessable Content error when submitting customer registration forms after adding an extension block with additional fields. The error occurs even when the new fields are left blank, but registration works normally when the extension block is removed.

Suggested troubleshooting steps:

  • Verify additional fields are properly configured as optional (not required in backend)
  • Check for syntax or logical errors in the extension code
  • Remove added fields one at a time to identify which causes the issue
  • Inspect server logs for specific error messages related to the additional fields
  • Ensure field formats are correct (e.g., date fields properly handle blank inputs)
  • Confirm the form structure is correct and fields are properly nested

The issue appears related to how the extension block processes or validates the additional fields during form submission, even when they contain no data.

Summarized with AI on November 16. AI used: claude-sonnet-4-5-20250929.
1

Hi,
I’m facing with an error 422 Unprocessable Content after customer registration. I’ve added an extension block to the customer/register page, which extends the customer registration form. However, even when the additional fields are not filled in, I still encounter this 422 error. When I remove my block, it works as expected.

Examples:

  1. With added extension block:
POST [https://your-store.myshopify.com/account](https://your-store.myshopify.com/account)
Status code: 422 Unprocessable Content
Payload:
form_type: create_customer
utf8: ✓
customer[first_name]: Rosalyn
customer[last_name]: Williamson
customer[email]: joqizy@mf.com
customer[password]: !123

X-Request-Id: 10e86098-c62a-4146-b20f-c5e3bb52a607
  1. Without added extension block:
POST [https://your-store.myshopify.com/account](https://your-store.myshopify.com/account)
Status code: 302 Found
Payload:
form_type: create_customer
utf8: ✓
customer[first_name]: Kirk
customer[last_name]: Hodges
customer[email]: lavohyryk@mf.com
customer[password]: !123

X-Request-Id: 4458e6cf-ba64-416f-9f04-e370cfb35623
2

Hi Manfa,

An 422 Unprocessable Entity error can occur due to various reasons, such as invalid data or incorrectly formatted input. In your case, it seems the error is likely due to the additional fields that you added the customer registration form using the extension block.

Even though these fields are not mandatory and you’re not filling them in, they might still be processed when the form is submitted. If these fields are not properly configured or are missing some required attributes, it could lead to a 422 error.

Here are a few things you can do to troubleshoot this issue:

  1. Confirm the additional fields are optional: Ensure that the additional fields you added are indeed optional. If they’re set as required fields in the backend but left blank, it could cause a 422 error.

  2. Check the format of the fields: Verify that the additional fields are correctly configured. For example, if you have a date field, ensure it’s formatted correctly and can handle blank inputs.

  3. Inspect server logs for more information: The server logs can provide more specific information about the error. Look for any error messages related to the additional fields.

  4. Remove fields one at a time: If you added multiple fields, try removing them one by one to identify the field causing the issue.

  5. Check your code: Make sure there are no syntax or logical errors in your code. Also, verify that your form is correctly structured and all fields are properly nested.

Try out the above and let us know if you’ve still experiencing issues - hope this helps,

1 Like