Warning: DOMDocument::loadHTML(): htmlParseEntityRef: expecting ';' in Entity,

This error message indicates that there is an issue with an entity reference in the HTML code being parsed by the DOMDocument class. An entity reference is a way of representing a special character (such as < or &) in HTML. The error occurs when the parser expects a semicolon (;) to terminate the entity reference, but it is missing or malformed.

$html = '<p>This is a &nbsp test</p>'; // Missing semicolon after &nbsp
$dom = new DOMDocument();
$dom->loadHTML($html);

To resolve this warning, you can either fix the malformed entity in your HTML string or suppress the warning during parsing. The most common approach in PHP is to enable internal libxml error handling:

libxml_use_internal_errors(true);
$dom = new DOMDocument();
$dom->loadHTML($html);
// Optionally clear errors: libxml_clear_errors();

For a more robust solution, ensure all special characters are properly encoded before passing the string to DOMDocument::loadHTML(). You can use htmlspecialchars() to convert problematic characters to safe entities:

$safeHtml = htmlspecialchars($rawInput, ENT_QUOTES | ENT_HTML5, 'UTF-8');
$dom = new DOMDocument();
$dom->loadHTML($safeHtml);