Hi Yeras,

thank you for your help!
Nevertheless, I think it has something to do with the color.
Try:
//Series_m0.FillSampleValues(25);
Series_m0.addxy(1,2,'d',clGreen); // <--
Series_m0.addxy(4,5);
in your Simple_project and you will get the index error, sure.

Thanks and regards
Reinhard