Hi all , i have create a custom data source with VS2005 that's work fine with VS 2008 report server project but when i have have add a report to the report library in sharepoint - that was integrated with SSRS 2008 - the report throw this error An error has occurred during report processing. (rsProcessingAborted) Cannot create a connection to data source 'DataSource1'. (rsErrorOpeningConnection) Request for the permission of type 'System.Security.Permissions.SecurityPermission, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed. so any suggestions ...

Hi amir_samir, The issue might be caused by the code in the custom data extension is not trusted to execute. In order to troubleshoot the issue, could you please try to set the following code group to FullTrust to check if the report works fine? </CodeGroup> <CodeGroup class="FirstMatchCodeGroup" version="1" PermissionSetName="FullTrust" Description="This code group grants MyComputer code Execution permission. "> <IMembershipCondition class="ZoneMembershipCondition" version="1" Zone="MyComputer" /> The code group is existing in rssrvpolicy.config in folder <Install Driver>:\Program Files\Microsoft SQL Server\MSRS10.<Instance Name>\Reporting Services\ReportServer by default. Please also make sure the custom assembly is frull trusted. For more information about Code Access Security in SQL Server Reporting Services(SSRS), please see: http://msdn.microsoft.com/en-us/library/ms154658.aspx If you have any more questions, please feel free to ask. Thanks, Jin Chen Jin Chen - MSFT