ASP.Net: Error executing child request for ChartImg.axd

Sorry to all Revit API readers, this one isn’t really relevant to you.

I’ve been working on an ASP.Net project, making use of the awesome free charting tools from Microsoft. I made a form that posts back and generates a column graph based on the inputs and some database calls. A problem I kept running into was an error message that says:
”Error executing child request for ChartImg.axd”

After looking around on the net and reading through some forum posts, I discovered to fix this you just need to make a small change to your web.config.

The problem arises as I was using postbacks to generate my chart, you must add support for this in your httpHandlers section of the web.config by changing:

   1: <add path="ChartImg.axd" verb="GET,HEAD" type="System.Web.UI.DataVisualization.Charting.ChartHttpHandler, System.Web.DataVisualization, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"/>

To:

   1: <add path="ChartImg.axd" verb="GET,HEAD,POST" type="System.Web.UI.DataVisualization.Charting.ChartHttpHandler, System.Web.DataVisualization, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"/>

The only change between the two is in the “verb=” property I added “,POST” to the end.

After this all should work fine.