I added a custom .html email template at THEME\Magento_Email\email\usp_block.html (i also tried THEME\Magento_Email\view\frontend\email\usp_block.html).
Then I added the file THEME/etc/email_templates.xml with this content:
<?xml version="1.0"?> <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Email:etc/email_templates.xsd"> <template id="design_email_usp_block_template" label="USP Block" file="usp_block.html" type="html" module="Magento_Email" area="frontend"/> </config> Now I added a new template in the Magento Backend at Marketing -> E-Mail Templates and tried to include my template like this:
{{template config_path="design/email/usp_block_template"}} Then I flushed the cache. But if I preview, then I get this:
Error while filtering the template: The email template 'design_email_usp_block_template' is not defined.

