500 error on Ajax request when use ShopKeeper

[wax100]

when U try to add product to basket , 500 error appear in plugin seoPro

case 'OnLoadWebDocument': $template = ($modx->resource->get('template')) ? (string)$modx->resource->get('template') : '';
Because $modx->resource is NULL;

So, I suggest to add before this line
if(!$modx->resource){ break; }