Wordpress base page error
That message is misleading and we'll need to fix that.   Using the home page as the base page just won't work.  A WP Page needs to be created and set as the base page.
There should be (depending on your version) a System Alert that reads:
CiviCRM relies upon a base page in WordPress at http://example.org/, but it is missing. The default is https://example.org/civicrm, which does exist on this site. You can set the correct base page in the WordPress integration settings.

CiviCRM needs a WP page set as the basepage.  This should be set in wp-admin/admin.php?page=CiviCRM&amp;q=civicrm/admin/setting/uf&amp;reset=1  New installs create 'civicrm' as a WP Page and set that as the basepage.