TWebFileUpload issue

WEB TMS WEB Core
2

if I give my form the same id as the TWebFileUpload, then I get a different error when the form is loaded

procedure TFileUpload.UpdateElement;
var
  el:TJSHTMLElement;
begin
  inherited;

  CreateCSS;

  if Assigned(ElementHandle) then
  begin
    ElementHandle.style.setProperty('display','flex');

    el := TJSHTMLElement(ElementHandle.children[0]);
    el := TJSHTMLElement(el.children[0]);

    if not ShowPicture then
       el.style.setProperty('display','none') //<--- HERE
    else
      el.style.removeProperty('display');