Fatal Error with Post_Author shortcode

[EkoJR]

Fatal error: Uncaught Error: Call to a member function has_prop() on boolean in /home/ekojrc6/public_html/root_advancedpostlist/-apl-main/wp-content/plugins/advanced-post-list/includes/class/class-apl-shortcodes.php:639 Stack trace: 
#0 /home/ekojrc6/public_html/root_advancedpostlist/-apl-main/wp-includes/shortcodes.php(319): APL_Internal_Shortcodes->post_author('', '', 'post_author') 
#1 [internal function]: do_shortcode_tag(Array) 
#2 /home/ekojrc6/public_html/root_advancedpostlist/-apl-main/wp-includes/shortcodes.php(197): preg_replace_callback('/\\[(\\[?)(post_a...', 'do_shortcode_ta...', '[post_author]') 
#3 /home/ekojrc6/public_html/root_advancedpostlist/-apl-main/wp-content/plugins/advanced-post-list/includes/class/class-apl-shortcodes.php(220): do_shortcode('[post_author]') 
#4 /home/ekojrc6/public_html/root_advancedpostlist/-apl-main/wp-content/plugins/advanced-post-list/includes/class/class-apl-core.php(800): APL_Internal_Shortcodes->replace('<a href="[post_...', Object(WP_Post)) 
#5 /home/ekojrc6/public_html/root_adv in /home/ekojrc6/public_html/root_advancedpostlist/-apl-main/wp-content/plugins/advanced-post-list/includes/class/class-apl-shortcodes.php on line 639

Create & Add a post_list with internal shortcode [post_author] to a widget (page as well possibly). Then go to page that has widget. Possibly with multiple post lists.