Plot blank data then plot actual causes runtime error?

Hi I was wondering why you would get a runtime error with the values property when you plot blank data first, then plot some actual data after that with the same chart?

For instance:

ActiveChart.SeriesCollection(1).Values = 'actual data'
ActiveChart.SeriesCollection(1).Values = 'blank data'
'cause runtime error when running code below
ActiveChart.SeriesCollection(1).Values = 'actual data'

would cause a runtime error? I am getting this bug right now.

I have included a sample test which graphs actual data, then blank, and then errors when u plot the same actual data again.

Just activate/deactivate sheet1 to plot different data. thanks!