NullReferenceException exception setting chart gallery property

[User (Legacy)]

I'm using ChartFx for winforms.

chartfx.dll Version 6.0.839.0, (6.0.1353.24751)

chartfx.base.dll Version 6.0.839.0, (6.0.1353.24702)

chartfx.borders.dll Version 6.0.839.0, (6.0.1353.24718)

I have a Gantt chart with the Y (horizontal) axis as time.

Occasionally, we get an exception setting the chart gallery property:

System.NullReferenceException: Object reference not set to an instance of an

object

at SoftwareFX.ChartFX.14.HM(Int32 1M0, Gallery 1M1, IGalleryType 1M2,

Boolean 1M3, Boolean 1M4)

at at SoftwareFX.ChartFX.Chart.set_Gallery(Gallery value)

The calling code is along the lines of:

With Me.chart1

.ClearData(ClearDataFlag.Data)

' disable various commands

.Grid = ChartGrid.Horz

.SmoothFlags = SmoothFlags.None

.Scrollable = False

.Gallery = Gallery.Gantt

end with