Why is my Menu and dashboards not working on clean installation on Wordpress?
I had a similar situation on a new installation of CiviCRM on WordPress, but the hostname had changed from when it was first installed, and https had been enforced. 

Updating wp-content/uploads/civicrm/civicrm.settings.php and changing all relevant URL's to the new https URL then reloading the page was enough to get the menus to show.