I'm doing a migration of a handful of WP blogs (across multiple domains) for a friend from his host to a new Gandi Simple Hosting PaaS instance. I got WP 3.5.1 installed easily and followed Otto's instructions for installing the MU plugin.
The primary site, which won't host any actual content is: network.example.com. It will be the overall dashboard site for the network. The other sites are: family.example.com, (www).business1.com and (www).business2.com.
I seem to be running into an issue with the domain mapping. I've configured family.example.com as a network site and I'm unable to get logged into it. I also can't get anything to show up in Domain Mapping: Domains. I've tried adding domain, but nothing sticks. Whenever I load that page, I get the following error in my php.log
[05-Feb-2013 07:21:14 UTC] PHP Warning: Creating default object from empty value in /srv/data/web/vhosts/network.example.com/htdocs/wp-content/plugins/wordpress-mu-domain-mapping/domain_mapping.php on line 214
Any idea what's going on here? Do I even need the MU plugin? It seems that with 3.5.1, my network can contain sites across multiple distinct domains.