want to use 2byte charactor for username

 I want let user to use 2byte character for username when they register.

I have changed code for following field.

Admin -> Builder -> Field Builders>Join Form>Nickname>Advanced Section>check field

return (bool)( preg_match( '/^[a-zA-Z0-9_-]+$/u', $arg0 ) and !file_exists( $dir['root'] . $arg0 ) );

It was working before but it don't work now. I use dolphin 7.1.4

Is there any one know why it doesn't work with D7.1.4?

I want to let user to use chinese, japanese and korean character for their user name.

Thanks,

Any one??

 You'll need to look into multibyte support.