Thanks for your feedback. Your issue is caused by the feature that lets the plugin automatically select children of a given post type in your current sidebars. Therefore the error is not seen with posts, because these are not hierarchical.
However, mt1.meta_key = '_cas_post_types' should not be there and that is the problem. What other plugins are active on your site? Can you deactivate them all and reactivate them one by one where you check if you still get the error. That way we can confirm/refute that it is another plugin being incompatible with Content Aware Sidebars.