In our Entra External ID tenant, we are unable to create users with self-service sign up.

Question

In our Entra External ID tenant, we are unable to create users with self-service sign up.

When we create a flow, and connect the Application Registration, we get:

AADSTS39927:User creation failed during self-service sign-up.

Is there any steps in particular we can use to troubleshoot this issue?

Even when enabling flagging, no logs show up for the sign up event to any further detail to the failure.

Prompt assistance will be greatly appreciated.

Answer 1

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Hello @Anton Elisee ,

I understand the frustration. This error basically means "I collected the user's info, but the database refused to save it."

Since the regular logs aren't helping, Check 3 things:

1. Look at the Audit Logs, not Sign-in Logs: Because the user wasn't created yet, the "Sign-in" log is often empty. Go to the "Audit Logs" section in the menu. Look for a failed event that says, "Create User." Click on it, it usually tells you exactly why it failed """""like "Password was too weak" or "Email already exists"""""
2. Turn off "API Connectors" If you have them of course: Do you have any external code checking the user's data like an ID verification tool or a webhook??? If yes, that tool might be rejecting the user or crashing. Try removing that connection from your User Flow settings temporarily. If the sign-up works after that, you know the problem is in that external code.
3. Check your Sign-Up Form fields: Are you asking for a special custom field like "Shoe Size" or Employee ID???? Try removing custom fields from the form one by one. Sometimes a field is set to "required" but isn't set up correctly in the backend, causing the save to fail.

This may help you pinpoint the issue a least, let me know if you find something in the audit logs

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