RemoveAllDrawingObjects() causes "Object reference not set to an instance of an object"

I have a workbook with several worksheets (sample enclosed), two of which contain Excel charts (see sheets 8 & 9). When I open the Workbook with Aspose.Cells, I would like to remove all the existing charts and replace them with new charts. I am able to create the new charts without trouble, but am not able to completely remove the existing charts from the last time the workbook was saved.

What I am trying is:

sheet.Cells.Clear();
sheet.Charts.Clear();
sheet.RemoveAllDrawingObjects();

The third line here throws an exception: "Object reference not set to an instance of an object".

I'm using Aspose.Cells.dll FileVersion 4.4.0.6.

Is there another way to completely remove the existing charts/drawing objects?

Hi,

Thanks for considering Aspose.

Yes, we found the problem, we will figure out the issue soon.

Thank you.

Very good.

Thank you.