I recently moved several reports over to a new server. Everything works fine displaying tables and data, but charts are not displaying properly. It looks like the image is not r
Someone had a similar problem and the solution was to repair the SQL Server installation. I know it is quite long to run but it might be worth a try.
Equivalent topic in SO
You can try restarting the report server. That worked in my case with Sharepoint and SQL Server 2012. Or repair the SQL server installation on the server as some posts suggest.
SSRS 2012 Charts Not Rendering
I had the same issue when deploying a new report locally.
I restarted my Report Server service and the reports rendered fine.