Please, check if the following forum post illustrates your issue Silverlight Report Viewer - Report is Unavailable or Session is Expired
. More details about running Telerik Reporting with Azure can be found in the following blog articles:
If none of the suggested relates your issue, elaborate on it - what is exactly the message you see, whether without charts the report runs normally, if running the project outside the cloud is successful.
Feel free to open a support ticket and send us a sample project that we can test and we will update the forum thread with the result of our discussion in the end.
the Telerik team
Telerik Reporting Q1 2013 available for download with impressive new visualizations. Download today from your account.