PHP Warning: Empty string supplied as input

Hi,

thank you for your feedback.

Can you try to add this code in the file (/plugins/wp-seopress/inc/functions/sitemap/template-xml-sitemaps-single.php):

at line 137, replace with this:

							if ($post_content !="") {
								if (function_exists('mb_convert_encoding')) {
									$dom->loadHTML(mb_convert_encoding($post_content, 'HTML-ENTITIES', 'UTF-8'));
								} else {
									$dom->loadHTML('<?xml encoding="utf-8" ?>'.$post_content);
								}

								$dom->preserveWhiteSpace = false;

								if ($dom->getElementsByTagName('img') !='') {
									$images = $dom->getElementsByTagName('img');
								}
							}

Save the file and let me know if you still see the warning.

Hope it helps!