I don’t use custom compiled code often with the SQL Reporting Services reports I develop, but I came across a client the other day who was migrating SQL Server 2008 R2 reports (Native Mode) to SQL Server 2012 SP1 (SharePoint integrated mode). A number of these reports were using custom DLLs for some logic and formatting. I quickly realized that I had not migrated reports utilizing custom DLLs from native mode to SharePoint Integrated mode. As such, I was a little perplexed as to where I should install the DLLs so that SharePoint would recognize and utilize them when the report rendered.
In native mode, you would simple copy the DLL over to the bin directory within Reporting Services. Something similar to the following:
C:\Program Files\Microsoft SQL Server\ MSRS10_50.SQLSERVER\Reporting Services\ReportServer\bin\MyCustomReportItem.dll
However, I was not finding a reference to where to place the DLL when Reporting Services was running in SharePoint Integrated mode (as a native service). I had to call on some of the Reporting Guru’s at Catapult Systems, and they indeed directed me to the correct location on the SharePoint App Server:
C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\WebServices\Reporting\bin\MyCustomReportItem.dll
Once I placed the reporting DLL in this location, the reports rendered in SharePoint without any further issues.
For more information about custom DLLs and reporting services, have a look at the following MSDN topic (Custom Report Items) :