Fatal error: Call to a member function cache_size() on null

[RavanH]

Related thread on WP.org forums https://wordpress.org/support/topic/fatal-error-call-to-a-member-function-cache_size-on-null/

[06-Nov-2018 15:13:17 UTC] PHP Fatal error:  Uncaught Error: Call to a member function cache_size() on null in /home/xxx/public_html/wp-content/plugins/cache-enabler/inc/cache_enabler.class.php:822
Stack trace:
#0 /home/xxx/public_html/wp-content/plugins/cache-enabler/inc/cache_enabler.class.php(789): Cache_Enabler::get_cache_size()
#1 /home/xxx/public_html/wp-includes/class-wp-hook.php(286): Cache_Enabler::add_dashboard_count(Array)
#2 /home/xxx/public_html/wp-includes/plugin.php(203): WP_Hook->apply_filters(Array, Array)
#3 /home/xxx/public_html/wp-admin/includes/dashboard.php(316): apply_filters('dashboard_glanc...', Array)
#4 /home/xxx/public_html/wp-admin/includes/template.php(1073): wp_dashboard_right_now('', Array)
#5 /home/xxx/public_html/wp-admin/includes/dashboard.php(230): do_meta_boxes(Object(WP_Screen), 'normal', '')
#6 /home/xxx/public_html/wp-admin/index.php(160): wp_dashboard()
#7 {main}
  thrown in /home/xxx/public_html/wp-content/plugins/cache-enabler/inc/cache_enabler.class.php on line 822

seems to be happening on the admin dashboard.

[RavanH]

Occurs when Permalinks are not set.