PowerPivot for SharePoint: Failed to render chart
Problem: on a SharePoint 2010/PowerPivot 2008 R2 environment, users would receive a 'Failed to render' chart' error
Based on previous experience I tried the following but all came back negative
Is PowerPivot feature enabled at the site collection? Yes
Recycled app pools - error still occurs
Verified that CT2WTS is enabled on every server running Excel Services - Yes
Resolution: NOTE: I highly recommend you plan for PowerPivot instead of just installing it. You need to plan for proper hardware and software configurations to ensure that it runs smoothly. You should also understand the data that is going to be put into your farm. How many PowerPivot workbooks? How large are they? How complex is the data they are pulling in? What external systems do they need access to? None of these were addressed in this case, the following resolution was something that had to be done quickly in order to get past the issue in production. Now I am working with the customer to scale out their BI environment so that we can stop addressing these issues with 'quick fixes'. see my recommended reading suggestions below
Reinstalled the PowerPivot farm solutions.
Stopped the Excel service on all servers, except one server. (this was done so we could more easily identify the problem server)
Restarted the Claims to Windows service and Excel services.
Increased the following settings within PowerPivot.
Maximum Request Duration
Volatile Function Cache Lifetime