20x6

Helen-

Unfortunately I have not had time to test my suggested fix yet, so it may not get to the root of the issue. I should point out that not every field needs to be changed, only multiline fields like ‘nm_wpregistration_new_user’ . My suggestion is to try reverting all your code changes, and then only change the sanitize_text_field function to sanitize_text_area and see if that fixes your issue.

I can confirm this is an issue for me as well. The sanitize_text_field on the email setting field needs to be changed to sanitize_text_area in order to preserve line breaks:

$sanitized_settings['nm_wpregistration_new_user']		= sanitize_text_field($_REQUEST['nm_wpregistration_new_user']);

The same goes for all textarea fields in the settings section: nm_wpregistration_form_css, nm_wpregistration_form_desc nm_wpregistration_terms_condition etc. This is a fairly new function, (4.7.0) so some backward compatibility checks should be added as well.