I am evaluating the Nevron Chart for Sharepoint 2009 Vol 2 version and I am impressed and excited at what I have been able to achieve through the web part. After running the 'Run Chart Designer' and connecting to my datasource, I can create the charts I need and preview them. However the problem I have is when I am finished and want to 'publish/display' the chart on my Sharepoint site (by clicking the apply or ok button) the Nevron Webpart display a box with an error message in it that says;

" The following error occurred while updating the chart: ConnectionString cannot be an empty string."

Can someone help me with this?