Registration Error Incorrect Code.

I deactivated the k2 and used the original Joomla contact form. I got the same error.

It is not same , this is invalid token error. It appears when you dont have this:

<?php echo JHTML::_( 'form.token' ); ?>

within registration form tag.

Its strange because we don't have registration form override for template, joomla default is used. Did you maybe created that???

I am not really sure anymore, k2 has been deactivated, is this the normal registration form?

www.wellhoo.com/index.php/de/anmelden?view=registration

Do you have files on this path:

/templates/hot_destination/com_users/registration/

I do not even have com_users in hot_destination. I migrated the site with Akeeba, could that be an issue?

Can you then check:

components\com_users\views\registration\tmpl\default.php

if you have <?php echo JHtml::_('form.token');?> there??