Although this is tagged as relating to the "Set Password" plugin, I couldn't find "No email Required" in the list of plugins when making this post!
I've just installed & activated the no email required plugin and whilst it removes the need for the user to click the verification link, the signup page is still validating the email field and throwing an error when it's left blank (see screenshot). http://schblogs.com
It seems that the following is being triggered: (line 473 in ms-functions.php)
if ( !is_email( $user_email ) ) $errors->add('user_email', __( 'Please enter a correct email address.' ) );
According to the comments this error can be unset using the "wpmu_validate_user_signup" filter. I didn't see any mention of the filter in the plugin code so I'm assuming that it's not coded to do this?
I tried to read up on the WP_Error class to see if I could code my own fix to unset the error and share it here, but didn't manage to get my head round it... oO