Magento 2.3 some errors need fixing

Hi,

I am having a few issues with Magento 2.3 which needs fixing urgently. Please below:

1. I am unable to edit some configurable products that have large number of associated products assigned. I am getting this error: Warning: DOMDocumentFragment::appendXML(): Entity: line 1: parser error : internal error: Huge input lookup in /home/jsbfurniture/public_html/m2/vendor/magento/framework/View/TemplateEngine/Xhtml/Template.php on line 60

2. I am unable to delete products in bulk. I am getting the following message:

There has been an error processing your request

The "HP-1001-3'0 Single-No Drawers-Ascot-Single Platform Top-Ascot -" product couldn't be removed.

3. The image on configurable product view pages disappear after 2 - 3 secs.

I need this to be fixed urgently. Thank you