PHP error when creating a category with 2.6

Hi there,

I see the following PHP error thrown in the Admin interface when trying to add a new category to a set:

Fatal error: Call to a member function update_meta() on a non-object in /Users/<snip>/perch/core/apps/categories/PerchCategories_Categories.class.php on line 20

I had my set configured to use the default Set and Category templates that came with 2.6 but… no dice. I upgraded this morning from the latest 2.5x release and saw the "Update successful" screen, and I've added 'categories' to apps.php.

Any ideas? Thx much!

MG