Yaml12JSON schema fails with "Failed to unpack yaml node" "with tag '?'"

[JustinGrote]

Pretty simple to reproduce, not sure if I'm missing something obvious here.

[jborean93]

It's been a while since I last played with the YAML 1.2 JSON schema but AFAIK the input essentially has to be valid json values so "asdf": "test". The exception shown here can certainly be better but it's saying that a plain scalar value (unquoted) (and untagged value) can only work if it's a bool "key": true, int "key": 1, float "key": 1.1, or null "key": null. I'll try and see what is involved to make that error message better.