Populate Grid from Process Model

Hello, 

I would like to show an Array of values inside a grid.
These values are stored as Array of CDT inside a Process Model into a variable called Result.

I have created a const Rule of type Process Model with my process model:

Inside my Interface I have:

=load(
local!data: cons!DLF_constGetAllPrototype,
local!pagingInfo: a!pagingInfo(startIndex: 1, batchSize: -1, sort: a!sortInfo(field: "name", ascending: true)),
with(
local!datasubset: todatasubset(local!data.result, local!pagingInfo),
a!gridLayout(
label: "Metadati",
totalCount: count(local!data.result),
headerCells: {
a!gridLayoutHeaderCell(label: "Id" )
},
columnConfigs: {
a!gridLayoutColumnConfig(width: "DISTRIBUTE", weight:3 )
},
rows: a!forEach(
items: local!data.result,
expression: a!gridRowLayout(
id: fv!index,
contents: {
a!paragraphField(
label: "valore " & fv!item.description,
value: fv!item.description
)
}
)
)
)
)
)

Could not display interface. Please check definition and inputs. Interface Definition: Expression evaluation error at function 'todatasubset' parameter 2 [line 5]: Invalid index: Cannot index property 'result' of type Text into type Process Model

I'm very new to Appian and I think I have several errors, but I can't figure out.

Tks