Error message

• Notice: Trying to access array offset on value of type bool in simple_toc_node_handler() (line 306 of /home/vietdecor/public_html/sites/all/modules/simple_toc/simple_toc.module).
• Notice: Trying to access array offset on value of type bool in simple_toc_node_handler() (line 308 of /home/vietdecor/public_html/sites/all/modules/simple_toc/simple_toc.module).