Tags, breadcrumb and category page buttons of posts show errors

Hi,

I have created a page (called Video Exercises) and assigned it to the ‘Blog’ template.

I have selected the slugs of the categories I want to show posts from.

I have also given the posts tags and placed a tags widget and also a blog categories menu widget in the sidebar of the ‘Video Exercises’ page.

The problems are that when I click the following buttons to navigate the post pages, they all come up with the following errors…
– Clicking an of the tag buttons: Fatal error: Cannot use object of type WP_Error as array in /home/quaminaadmin/public_html/wp-content/themes/AegaeusWP/archive.php on line 46
– Clicking any category button: Fatal error: Cannot use object of type WP_Error as array in /home/quaminaadmin/public_html/wp-content/themes/AegaeusWP/archive.php on line 46
– Clicking any button in the breadcrumb area (once within any post’s page): Fatal error: Cannot use object of type WP_Error as array in /home/quaminaadmin/public_html/wp-content/themes/AegaeusWP/archive.php on line 46

The URL is http://www.physicaldefence.com/ where you can see for yourself. Can you please advise me on how to resolve this issue.