Your code works because you have a "New" each time you open Form2.
In VB, you don't have to do the "New" and that cause the issue.
(In the second call, the form is in memory)

Regards.

Sorry but I can't access to newsgroup or upload page from my Office. It's very simple to do: 1) Create a new project with Form1 2) Add a new Form2 3) Put a button on Form1 and add "Form2.showDialog()" in the Button_Click 4) On the Form2, put a chart and a button to close the form Run and open twice ...

Hi,

I have the same error with the chart in a dialog box (at the second call of the box).

So, I have add "Chart1.Chart.Graphics3D.BackBuffer = Nothing" in the Form_Load to workaround...

Regards.