Dataview Table Orphans (frontmatter)

Help
3

My frontmatter is:

author: Name
title: tbs frontmatter
subtitle: XXX
aliases: 
parent: "[[☝️-index-XXX]]"
prio: 0
frist: 00-00-00
tags:

and on your code-proposal I get the following message:

Dataview: Every row during operation ‘where’ failed with an error; first 3:

  • Unrecognized function name ‘exists’
  • Unrecognized function name ‘exists’
  • Unrecognized function name ‘exists’

Many thanks for your hints.