Following error is occurring while trying to access report server or report manager in SQL Server Reporting Service 2005.
An ASP.NET setting has been detected that does not apply in Integrated managed pipeline mode
Reporting Services in SQL Server 2005 runs as on IIS 7.0. After configuring Reporting Service, two virtual directories will be created by default their Application pool is DefaultAppPool.
Every Application pool has Pipeline mode and there are two types of Pipeline modes namely, Integrated and Classic.
If the Pipeline mode of the Application Poll attached to virtual servers is Integrated you will get the above error.
You need to change the Integrated to Classic as shown below in IIS.
You do not have to restart neither IIS nor SQL Server Reporting Services.
There is another method. You need to create new application pool with Classic and attached that Application pool to the both virtual servers from Reporting Server Configuration Tool.