Yaml frontmatter didn't convert to Properties

In the post below I show a query which might help you locate the offending frontmatter sections at least. This way you can focus your efforts on which files have bad yaml, and hopefully you’ll start seeing a pattern of what to change to make the yaml valid, which in turn will automatically make it into properties.

The post above should also be the answer to Query for notes with invalid YAML? (which has closed recently), but where a similar question where asked by @chrisdwells and @joshuawagner .