Dear Sir/Madam, I have installed the Wordpress at domain

Dear Sir/Madam,

I have installed the Wordpress at domain news.china.com.au with network enabled. And previously I have created a few sites under the folder like news.china.com.au/test, they are all fine.

Until I have installed the plug in Domain Mapping and Multisite plugins from you. When I create the site news.china.com.au/carsvale, it comes up the following error:

Warning: Creating default object from empty value in /home/chinacom/public_html/news/wp-includes/ms-functions.php on line 1502

Warning: Cannot modify header information - headers already sent by (output started at /home/chinacom/public_html/news/wp-includes/ms-functions.php:1502) in /home/chinacom/public_html/news/wp-includes/pluggable.php on line 896

When I was trying to create it again, it says the site existed already. It seems actually the site was created even with the above error message.

Now I am trying to map the domain carsvale.com to the site news.china.com.u/carsvale
Under the control panel of wordpress Carsvale, I entered the like below:

But it pop up message as the domain is unavailable to access:

However, the domain was purchased years ago and I have created the A record, the zone file as:

And I have pinged news.china.com.au:

I have also pinged the carsvale.com:

I have carefully read your instruction on the website, it’s very detail and clear. Could you please guide me through in my case?

Best regards,
Hugh