anchor.diff:      on e: Exception do
       begin
         aError := e.Message;
  -      exit;
  +      Result := false;
       end;
     end;
  -  Result := true;
   end;
   
   function GeneratePNGThumbnail(const aSourceFile, aThumbnailsFolder: String; const aMaxWidth, aMaxHeight: word; out aThumbnailFileName: String; out aError: String): boolean;
  
positive.code:   if ext = '.pdf' then
    begin
      try
        TMutoolToolbox.ExtractThumbnailOfFrontPageFromPdf(aSourceFile, aThumbnailFileName, aMaxWidth, aMaxHeight);
        Result := true;
      except
        on e: Exception do
        begin
  
negative.code:   rateWidth, rateHeight : Extended;
    r : TRect;
  begin
    Result := true;
    try
      sourcePicture := TPicture.Create;
      thumbnail := TPortableNetworkGraphic.Create;
  