Update to WP 4.3 Broke CiviCRM Dashboard in CiviCRM 4.6.8
I wonder if you still need help with this or not. I tried to replicate with WP 4.3 and Civicrm 4.6.8 and dashboard was loading without any issues, i would suggest update your wordpress version to the latest at of now, 4.9.1 and i think problem will be solved.

Thanks