Range can't iterate over, nested front matter lists, nested ranges, page variables and empty interfaces

In my home (index.html) file I have this

{{ range $.Params.one.two }}
{{ partial "partial" (dict "context" .  "three" .three ) }}
{{ end }}

Inside the partial I have something like this

{{ range .three }}
{{ end }}

My front matter looks like this,

  - three: 
    - hello
    - world

This produces an error: range can’t iterate over

When debugging {{ printf "%#v" .three }}

[]interface {}{"hello","world"}

^ I think the empty interface is problematic. Any pointers?

It was a yaml formatting error. For anyone struggling with something similar try just using JSON in your front matter. Jesus.