Error code: AADB2C90261 - Azure B2C/Captcha related Error on Sign Up - azure-ad-b2c

Question

I am trying to sign up the users using Azure B2C(by doing this I am using MSAL with Angular),
by mail confirmation, captcha v2(google) and MFA.
For the first attempt I used just a normal sign up with the email and afterwards with MFA and had no issues creating the users.
Than I added captcha and in my sign-up, meaning that I needed to use a custom page.
To add captcha feature I used the following process from this link Link - Create Captcha with Azure B2C (regarding one step that is described in the article, the azure function was created in the portal, because locally I had some issues)
In my sign up page where you add the email address and all the claims of the user, after adding all the claims and checked the captcha feature, than press for create, appears the following message:
errorCode: "AADB2C90261" message: "The claims exchange
'PreUserWriteRestful' specified in step '1' returned HTTP error
response that could not be parsed." status: "400"
AADB2C90261 -Taken from Microsoft page - Error Code - The claims exchange '{0}' specified in step '{1}' returned HTTP error response that could not be parsed.
Also the MFA feature doesn't appear. What can be ? that I missed to do ? Or what it represents ?
Tested without MFA and the same issue persists
Did anybody that is using Azure B2C added captcha ?
Thank you.

Answer 1

I tried to reproduce the same in my environment and got below results:
Initially I deployed Azure Function via Portal and left index.js file as default like below:
I configured one API connector named Verify Captcha by adding above function URL in endpoint like below:
Now I added this API connector to my user flow like below:
When I ran the user flow by entering required details in Sign up page and checked the captcha feature, I got the same error as below:
To resolve the error, I tried deploying 2 Http Trigger Functions locally:
HttpTrigger1 - modified index.js file with this GitHub code
and installed required modules like below:
HttpTrigger2 - left index.js file with default code like below:
By updating properties in local.settings.json file, I deployed these functions to Azure:
{
"IsEncrypted": false,
"Values": {
"AzureWebJobsStorage": "",
"FUNCTIONS_WORKER_RUNTIME": "node",
"BASIC_AUTH_USERNAME": "xxxxx",
"BASIC_AUTH_PASSWORD": "xxxxx",
"CAPTCHA_SECRET_KEY": "6LfoQ9oxxxxx21BEE23-kPQkv6QIQt8",
"B2C_EXTENSIONS_APP_ID": "dcxxx0b0-d5xf-42x-b1a4-97xxx689x1"
}
}
Response:
When I checked in Azure Portal, functions are updated successfully like below:
I configured another API connector named Verify Captcha server side by adding above function URL in endpoint like below:
Now I updated API connector with above in my user flow like below:
I ran the user flow by entering required details in Sign up page and checked the captcha feature like below:
When I selected Create account, I got response like below:
It may take some time to complete the captcha like below:
When I tried the same with default index.js like HttpTrigger2, I'm getting same error as you. So, make sure to replace code in your index.js file with this GitHub code.
You can try the same in your environment locally to resolve the issue.