E801 - Template syntax error

Cause

The Jinja2 source of a template element (inline or via template_file), or its JSON5 front-matter block, failed to parse. A common cause is literal {{ inside generated content — e.g. a JavaScript template literal — which Jinja interprets as an expression.

Example

[ { html: "<script>let x = `${y}`; {{ broken</script>" } ]

How to fix

Fix the Jinja syntax at the reported line. Wrap literal {{ in {% raw %}…{% endraw %}. For front-matter errors, the block between the --- lines must be a valid JSON5 object.