I'm receiving this error message which is mentioned below, but as you can see in the image there are no XML updates, neither content, how can I fix it?
Please correct the XML data and try again. Element 'reference': This element is not expected. Expected is one of ( referenceContainer, container, update, move, head, body ). Line: 1
Probably there is an old XML in the database, check the cms_page table in the custom_layout_update_xml. When you find and remove the XML changes directly from the database it will be solved and you might be able to save your CMS Page normally.
It's happening because you updated your Magento and it was saved there before, this updated version didn't recognize the XML to render in the page to be removed or edited.