Editable Grid Problem

Hi all,

Could somebody tell me what is wrong with this code:

a!gridLayout(
 totalCount: count(local!data),
 headerCells: {
   a!gridLayoutHeaderCell(label: "Datum" ),
   a!gridLayoutHeaderCell(label: "Oznaka" ),
   a!gridLayoutHeaderCell(label: "Sreden" ),
   a!gridLayoutHeaderCell(label: "DrzavaAng" ),
   a!gridLayoutHeaderCell(label: "NazivAng" ),
   a!gridLayoutHeaderCell(label: "" )
 },
 columnConfigs: {
   a!gridLayoutColumnConfig(width: "DISTRIBUTE", weight:3 ),
   a!gridLayoutColumnConfig(width: "DISTRIBUTE", weight:3 ),
   a!gridLayoutColumnConfig(width: "DISTRIBUTE", weight:3 ),
   a!gridLayoutColumnConfig(width: "DISTRIBUTE", weight:3 ),
   a!gridLayoutColumnConfig(width: "DISTRIBUTE", weight:3 ),
   a!gridLayoutColumnConfig(width: "ICON")
 },
 rows: a!forEach(
   items: local!data,
   expression: a!gridRowLayout(
     id: fv!index,
     contents: {
       a!textField(
         label: "Datum "& fv!index ,
         value: fv!item.Datum,
         saveInto: fv!item.Datum,
         required: true
       ),
       a!textField(
         label: "Oznaka " & fv!index,
         value: fv!item.Oznaka,
         saveInto: fv!item.Oznaka,
         required:true
       ),
       a!textField(
         label: "Sreden" & fv!index,
         value: fv!item.Sreden,
         saveInto: fv!item.Sreden,
         required:true
       ),
       a!textField(
         label: "DrzavaAng" & fv!index,
         value: fv!item.DrzavaAng,
         saveInto: fv!item.DrzavaAng,
         required:true
       ),
       a!textField(
         label: "Naziv Ang." & fv!index,
         value: fv!item.NazivAng,
         saveInto: fv!item.NazivAng,
         required:true
       ),
       a!imageField(
                label: "delete " & fv!index,
                images: a!documentImage(
                  document: a!iconIndicator("REMOVE"),
                  altText: "Remove Entry",
                  caption: "Remove " & fv!item.Oznaka,
                  link: a!dynamicLink(
                    value: fv!index,
                    saveInto: {
                      a!save(local!data, remove(local!data, save!value))
                    }
                  )
                ),
                size: "ICON"
              )
     }
   ),
   addRowlink: a!dynamicLink(
    label: "Add Entry",
    saveInto: {
     a!save(local!data, append(local!data, save!value))
    }
 )
)

The error on test that it generated, when I add new row is :

Could not display interface. Please check definition and inputs. Interface Definition: Expression evaluation error at function a!forEach [line 102]: Error in a!forEach() expression during iteration 1: Expression evaluation error at function a!dateTimeField [line 107]: Invalid index: Cannot index property 'Datum' of type Text into type DataSubset

And when I try to remove it remove the whole table with the Remove Icon on the first row.

Thanks in advance,Natasa