I have this issue and I don't know how to solve it.
My phtml file is under:
app/design/frontend/rwd/josefsteiner/template/home.phtml
and i tried to include this phtml file into my CMS site like this:
{{block class="Magento\Framework\View\Element\Template" name="test_block" template="rwd_josefsteiner::home.phtml"}}
But i get always this error:
Error filtering template: Invalid template file: 'rwd_josefsteiner::home.phtml' in module: '' block's name: 'magento\framework\view\element\template_0'
how to fix this issue?