TfmEdit = class(TForm)

Var
fmEdit : TfmEdit;// нет этой строки

procedure CallEditForm(id: integer);
...
....
fmEdit := TfmEdit.Create(fmMain);

LayoutControl.Container.StoreToStream(stream, LayoutControl.Name);

function LoadStreamToStr(stream: TStream; count: integer): String;
var
  Bytes: TBytes;
begin
  Result:= '';

  if Stream.Size > 0 then
  begin
    SetLength(Bytes, count);
    Stream.Read(Bytes[0], count);
  end;

  Result := TEncoding.ASCII.GetString(Bytes);
end;

s := LoadStreamToStr(stream, 100);

if s.Contains(LayoutControl.Owner.Name) then
есть имя формы в сигнатуре стрима

    cxPropertiesStore1.StorageName := Form.ClassName;
    cxPropertiesStore1.StorageType := stStream;

    with TcxPropertiesStoreComponent(cxPropertiesStore1.Components.Add) do
    begin
      Component := form;
      for I := 0 to Length(APropsForm) - 1 do
        Properties.Add(APropsForm[i]);
    end;//with

     cxPropertiesStore1.StorageStream := Stream;
     cxPropertiesStore1.StoreTo;
     q.ParamByName('STREAM').LoadFromStream(Stream);
     q.ExecQuery;

    with TcxPropertiesStoreComponent(cxPropertiesStore1.Components.Add) do
    begin
      Component := form;
      Component.Name := '';
      for I := 0 to Length(APropsForm) - 1 do
        Properties.Add(APropsForm[i]);
    end;//with

Component.Name := '';