template/bad-filter-argument

A filter or function got an argument it can’t use: a missing or unknown one, a value of the wrong type, a dateformat format it doesn’t know, or a - key passed to Jinja’s own sort, which reads it as a field name.

Example

{{ entry.date | dateformat(format="iso") }}

Fix

Pass what the message asks for. A dateformat format is strftime directives, such as “%Y-%m-%d”, or “rfc2822” or “rfc3339”. To sort descending, use sort_by(["-count"]).