Unique Database Value not working

I've created a registration form with SA and added the Unique Database Value validation for the E-Mailaddress.

The Validation is not working, users can still register with the same E-Mailaddress again. Please have a look at the attached file.

Thx for any help

when testing the registration page, are you logged in? if you are logged in, and try to test the registration page with the same email address as the one you are logged in as, i could see that happening.

to prevent this, edit the Unique database value validation, and instead of using the session for the Key column value, set it to 0

I was not logged in.

But changing the value to "0" worked. But I dont' understand why "0" works.

the session must have been set.

if the key is set to use the session, it will allow the email address that belongs to that session to be used. This is so you can update your registration with the same email address, but another user will not be able to create a registration with the same email address.

using 0 for the key value by passes the check to see if the email address belongs to the logged in user.

Thank you Jason!