I realise that the Blog Templates plugin isn't a premium plugin, but I'm thinkin that the error that we are seeing could very well be because of the MultiDB plugin we are using.
the blog templates plugin is here: http://wpmudev.org/project/blog-templates
When I upload gb_templates.php to mu-plugins, I get the following error when simply trying to access my dashboard:
Parse error: syntax error, unexpected T_OBJECT_OPERATOR in /home/futd/public_html/wp-content/mu-plugins/gb_templates.php on line 239
The reason that I think it may be the MultiDB plugin is because I'm not running that on my local install and the Blog Template plugin is working fine on there
Cheers in advance