Fatal error: Uncaught TypeError: Argument 1 passed to DOMNode::replaceChild() must be an instance of DOMNode, null given in /home/kurs10321/www/public_html/emm/wp-content/plugins/markup-markdown/MarkupMarkdown/Parsedown/Extra.php:501 Stack trace: #0 /home/kurs10321/www/public_html/emm/wp-content/plugins/markup-markdown/MarkupMarkdown/Parsedown/Extra.php(501): DOMNode->replaceChild(NULL, Object(DOMElement)) #1 /home/kurs10321/www/public_html/emm/wp-content/plugins/markup-markdown/MarkupMarkdown/Parsedown/Extra.php(236): MarkupMarkdown\Parsedown\Extra->processTag('<html>\n<head>\n<...') #2 /home/kurs10321/www/public_html/emm/wp-content/plugins/markup-markdown/MarkupMarkdown/Parsedown/Parsedown.php(289): MarkupMarkdown\Parsedown\Extra->blockMarkupComplete(Array) #3 /home/kurs10321/www/public_html/emm/wp-content/plugins/markup-markdown/MarkupMarkdown/Parsedown/Parsedown.php(43): MarkupMarkdown\Parsedown\Parsedown->lines(Array) #4 /home/kurs10321/www/public_html/emm/wp-content/plugins/markup-markdown/MarkupMarkdown/Parsedown/E in /home/kurs10321/www/public_html/emm/wp-content/plugins/markup-markdown/MarkupMarkdown/Parsedown/Extra.php on line 501