Here you go. Try this. I just went ahead and cut and paste my fix (I found) here so you have it at the ready. Cheers.
I found a fix for the Array Warning, actually off of the WordPress Support Ticket site. Here is the work around.
/wp-includes/post-template.php file is the one you will edit.
Line 1039 of wp-includes/post-template looks like:
if ( in_array( $page->ID, $_current_page->ancestors ) )
if ( gettype($_current_page->ancestors) === 'array' && in_array( $page->ID, $_current_page->ancestors ) )
I also recommend you simply rename the original post-template.php file in case this does not work or creates additional problems.