preheader description contains "null" and missing other parameters

There is a problem in the description of %preheader()%

What is should show: The preview text must be contained within double quotes, which also may contain the *clipboard* keyword. Alternatively you can use clipboard directly or *selection* (that last one only works when used from a Smart Snippet)

The json text:

  "preheader.text": {
    "message": "The preview text must be contained within double quotes, which also may contain the $clipboardStarred$ keyword. Alternatively you can use $clipboardLiteral$ directly or $selectionLiteral$ (that last one only works when used from a Smart Snippet)",
    "placeholders": {
      "clipboardLiteral": {
        "content": "$1",
        "example": "clipboard"
      },
      "selectionLiteral": {
        "content": "$2",
        "example": "\"*selection*\""
      },
      "clipboardStarred": {
        "content": "$3",
        "example": "*clipboard*"
      }
    }
  },

RealRaven2000 / SmartTemplates

preheader description contains "null" and missing other parameters #321