We have a SSRS report that was being executed under SSRS 2008. This report has a Tablix with one Group and inside this Group there are hidden lines with Charts that can be toggled.
After the migration to SSRS 2008 R2, when we try to show the chart lines, this error appears:
An error occurred during client rendering. Object reference not set to an instance of an object.
There are no errors on SSRS logs:
library!ReportServer_0-16!2b64!10/11/2011-17:09:31:: i INFO: RenderFromSession('/Vulkan Reports/Qualidade/Indice de RCL')
webserver!ReportServer_0-16!2b64!10/11/2011-17:09:31:: i INFO: Processed report. Report='/Vulkan Reports/Qualidade/Indice de RCL', Stream=''
We are sure that exists data to the charts. The report runs without errors on SSRS 2008 and on BIDS. Exporting to Excel is working fine. Only the HTML renderer gives the error.