Print from fr3 file

sur-se

Hello. I'm having troubles to print a report from a fr3 file (fr3.18). I use the next code:

  if Dialog.Execute then
  begin
       with MyReport do
       begin
               LoadFromFile(Dialog.Filename);
               ShowReport;
       end; 
  end;

It always returns the next error: "Class not found preparedreport"
I've tried with ShowPreparedReport, LoadPreparedReport, PrepareReport , and all mix. I always get the same error code.
How can I print a saved report file fr3?