FileNotFoundException: File name: 'Microsoft.EnterpriseManagement.Reporting.Security'

Problem:  

You may not able to browse Reports after installing and uninstalling the MOM reporting.

And you may get the following error message in SQL Reporting Service log files

w3wp!extensionfactory!1!01/30/2008-13:37:53:: e ERROR: Exception caught instantiating Windows report server extension: Microsoft.ReportingServices.Diagnostics.Utilities.ServerConfigurationErrorException: The report server has encountered a configuration error. See the report server log files for more information. ---> System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.EnterpriseManagement.Reporting.Security' or one of its dependencies. The system cannot find the file specified.

File name: 'Microsoft.EnterpriseManagement.Reporting.Security'

   at System.Reflection.Assembly.nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, Assembly locationHint, StackCrawlMark& stackMark, Boolean

   throwOnFileNotFound, Boolean forIntrospection)

   at System.Reflection.Assembly.InternalLoad(AssemblyName assemblyRef, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection)

   at System.Reflection.Assembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection)

   at System.Reflection.Assembly.Load(String assemblyString)

   at Microsoft.ReportingServices.Diagnostics.ExtensionClassFactory.LoadAssembly(String name)

Root Cause:

When MOM is introduced to a SQL Reporting Service system, it modifies the configuration files of the SQL Reporting Service.

<Security>

      <Extension Name="Windows" Type="Microsoft.EnterpriseManagement.Reporting.Security.GroupAuthorization, Microsoft.EnterpriseManagement.Reporting.Security">

            <Configuration>

                  <Connection>

                        <ServerName>uswmclmomq02</ServerName>

                  </Connection>

            </Configuration>

      </Extension>

</Security>

<Authentication>

      <Extension Name="Windows" Type="Microsoft.EnterpriseManagement.Reporting.Security.GroupAuthentication, Microsoft.EnterpriseManagement.Reporting.Security">

            <Configuration>

                  <Connection>

                        <ServerName>uswmclmomq02</ServerName>

                  </Connection>

            </Configuration>

      </Extension>

</Authentication>

When you try to bring SQL Reporting Service 2005 back to it’s native mode, you may experience the issue you faced.

Resolution:

When MOM is being installed on top of SQL Reporting Service 2005, it takes the backup of the Reporting Service’s configuration files as:

RSReportServer.config.0 and

RSReportServer.config.1

Renamed one of these configuration files back to RSReportServer.config and restart ReportServer Windows Service and IIS.

NOTE: 

Sometimes (SCOM 2007) adds a Web.Config file to ReportServer folder and backs up the original Web.config to Web.Config.0. You have to rename it back to Web.Config.

Method II. [ResetSRS.exe]

Read "Uninstalling Operations Manager Reporting Services" section in

https://technet.microsoft.com/en-us/library/bb418760.aspx