When I copy a shape in my application and then attempt to paste it, I get the error shown in the attachment.

Transcribed:
The Paste transaction FailedRolledback
Error Log:
1. Paste failed on a single node: Object reference not set to an instance of an object.

Can someone give me hint for where to start looking for what I've done wrong?

Thanks,
Herb.

The information you've provided is not enough to conclude what the problem is. I advise you to send the sample project in which this error occurs to support@nevron.com and we'll tell you what's wrong with it.