Explanation: The ❰++❱ operator expects two arguments that have type ❰Text❱

For example, this is a valid use of ❰++❱: 


    ┌────────────────┐
    │ "ABC" ++ "DEF" │
    └────────────────┘


You provided this argument:

↳ $txt0

... which does not have type ❰Text❱ but instead has type:

↳ $txt1

Some common reasons why you might get this error:

● You might have thought that ❰++❱ was the operator to combine two lists:

    ┌───────────────────────────────────────────────────────────┐
    │ ([1, 2, 3] : List Integer) ++ ([4, 5, 6] : List Integer ) │  Not valid
    └───────────────────────────────────────────────────────────┘

  The Dhall programming language does not provide a built-in operator for
  combining two lists