[Solved]-Invalid temp images directory in chart handler configuration-Highcharts

Check if that folder exists on your server and give read/write permission to the user of the application pool your site is running for that folder.

Or you can simple move that temp folder inside the site root Es: "~/temp" and configure highchart to use that folder.

Or you can change your ChartImageHandler from

<add key="ChartImageHandler" value="storage=file;timeout=20;dir=c:\TempImageFiles\;" />

To

<add key="ChartImageHandler" value="storage=file;timeout=20;" />

So he will use the default windows temp directory