I have got a field defined as a rich text field and that's causing any unexpected error when printing picking tickets. Looks like there is a problem parsing rich-text fields on advanced PDF/HTML templates.
I have seen the suggestions to use third-party tools to render the rich text context without disturbing the formatting. I am not concerned about the formatting as long as the content is readable.
Any ideas, please.
Try wrapping the field in a CDATA section.
For example; <![CDATA[${item.description}]]>