I create an excel chart with VBA and then format the axis titles and fonts' size. The following code works well for the Horizontal axis
cht.SetElement msoElementPrimaryCategoryAxisTitleAdjacentToAxis
cht.Axes(xlCategory, xlPrimary).AxisTitle.Text = "Factor of Safety"
cht.Axes(xlCategory, xlPrimary).AxisTitle.Format.TextFrame2.TextRange.Font.Size = 15
However, the similar code for the Vertical axis
cht.SetElement msoElementPrimaryValueAxisTitleAdjacentToAxis
cht.Axes(xlValue, xlPrimary).AxisTitle.Text = "Depth [mCD]"
cht.Axes(xlValue, xlPrimary).AxisTitle.Format.TextFrame2.TextRange.Font.Size = 15
leads to the error 424 "Object required". Could you please tell me what happened ?