I'm new to this forum and I have a question for a problem that took several hours of my nerves and I can't get trough the problem.
I have a xlXYScatter Chart which I create in c# to export to excel table. All the data is importet correcrly and all charts are drawn correctly but when I try to create a Trendline in the chart it gives me allways the same error: "Trendlines method of series class failed". I don't know what's wrong so if anybody could help me i would be very gradful. Tnx. the code is below: