We are using Server 2012 with SQL Server 2008R2. When I try to manage a report in SSRS, I get this error : operation is not valid due to the current state of the object. In looking for solutions I found this "On our systems, I found it to be related to KB2656355 (Server 2008 R2)"
We do not have this as we are on SQL 2012. I also found "You can override the value by adding the following key to the appsetttings section in your SSRS report manager web.config file (usually in Program Files\Microsoft SQL Server\MSRS10.MSSQLSERVER\Reporting Services\ReportManager)
<add key="aspnet:MaxHttpCollectionKeys" value="10000" />". We tried this and it didn't work.
The reports all run properly but I cannot manage them. Any suggestion?