error when using feeds JSONPath parser to create node

Backdrop noob here, but very experienced with Drupal 7, including doing very complex feeds imports with XSLT parsers and whatnot.

I'm trying to create the most basic of feeds importers using the JSONPath Parser. Here is the JSON that I am trying to import: {"title": "Lorem Ipsum"}. If I run the importer, I get the error "No filter class exists for token [index]". A similar feeds importer using the CSV parser works just fine, BTW.

Am I missing something obvious?

I am attaching screen shots of my feeds importer configuration and the error.

I must say that my first venture into Backdrop has been rather frustrating so far. I'm starting to wonder if I've made the wrong choice of CMS...