If a chart that was created goes into the negatives I have not been able to get the labels to show up appropriately. I used the ValueAxis property and set the TickLabelPosition to Low. This did nothing in my chart after I re-ran it. I was able to create the same chart in Aspose Slides, which was having the same problem, and used the same property and it worked correctly. I am currently using Aspose Cells for .Net version number 126.96.36.199. So I guess I am really wondering if this has already been fixed in a more recent release or is this something that would need to be scheduled to be released in the future.