PHP warning on vponepagecheckout

[JacoboPS]

Hello, checking my site, I have discovered this PHP Warning:

[29-Sep-2015 16:03:16 America/Detroit] PHP Warning: DOMDocument::loadHTML(): Empty string supplied as input in /home/xxxxxx/public_html/plugins/system/vponepagecheckout/cart/cartview.html.php on line 246

But I'm don't understand  what the Warning is telling me, so I don't know how to solve it.

This is the code from 239 to 251 lines:

// Get payment options
            $this->lSelectPayment();
            $payment_html = $this->renderPlgLayout('default_payment');
            $payment_script = array();
            $payment_scripts = array();
            $dom = new DOMDocument;
            $dom_state = libxml_use_internal_errors(true);
            $dom->loadHTML($html);          => this is line 246
            libxml_clear_errors();
            libxml_use_internal_errors($dom_state);
            $scripts = $dom->getElementsByTagName('script');
            if($scripts->length)
            {

Could you please help me to understand -and solve- what is happening here?

Thank you very much!

[GJC Web Design]

1. sorry -- 3rd party extensions aren't supported -- ask VPlanet

2. It is only a warning .. does no harm-- in a perfect world of course it should be got rid of

[JacoboPS]

1. sorry -- 3rd party extensions aren't supported -- ask VPlanet

2. It is only a warning .. does no harm-- in a perfect world of course it should be got rid of

Thank you GJC. I know it is only a warning, but sometimes when trying to isolate a problem, I prefer to get rid of all potential problems (or warnings). I'll look for VPlanet.

[GJC Web Design]

assume something like

if(isset($html)){
$dom->loadHTML($html);
}