I have tried to observe the requirement specified. Have you tried using the following sample application shared on your end: http://www.aspose.com/docs/download/attachments/56852539/RenderingExtensionDemo.zip?version=1&modificationDate=1368438801480
Can you please share which version of Aspose.Slides for Reporting Services you are using on your end and what is your environment details.
For your kind reference, I have also attached the sample application that I have compiled using Aspose.Slides for Reporting Services 4.8.1 without any issue. It seems you are probably missing to add the dll reference in project.
I have tried to understand the issue shared by you. In your first post you mentioned that you had issue while using the sample code shared in this documentation article. Now, I am assuming that you have passed stage 1 and generated the custom assembly TestSlidesRenderingExtension.dll after successful execution of sample project shared. You then followed the guidelines shared here to integrate the created assembly in Report server and got the issue. Am I right till here?
Can you please share the answer to following questions:
Which version of SQL Server is installed along with Report Server?
Are SQL Server and report server installed on same machine?
Does Aspose.Slides for Reporting Services normally if you do not deploy the custom assembly on your end?
I also like to add further that Aspose.Slides for Reporting Services does not work if you have SQL Server express installed on your end. Please also provide rssrvpolicy.config andrsreportserver.config for further investigation as well.
Thanks for sharing the requested information. I have created an issue with ID SLIDESREP-33305 in our issue tracking system as investigation so that our development team may help in further investigation and resolution of the issue. This thread has been linked with the issue so that you may be automatically notified once the issue will be resolved.
Our development team has investigated the issue on thier end and it has been observed that you have used DeviceInfo section inside of Configuration section which is wrong. Please use following configuration on your end.