Server Manager has stopped working. Problem Event Name: CLR20r2.

Hello everybody

We have a Windows 2012 R2 RDS Server, this server is also a DC.

This happend after an unkown task (may be an installation or update (No Windows updates) on the system)
We can't open the Server Manager and many other administrative tools (Event Viewer included). All user files were doubled with "_prior" at the end of the document name as you can see on the screenshot.

Error messages:
Server Manager has stopped working. Problem Event Name: CLR20r2.
Event Viewer: MMC could not create snap-in.

We exported the logs from Event Viewer:

3008
   A configuration error has occurred.
   24.03.2014 09:30:01
   24.03.2014 08:30:01
   e7bfe7da16144114af87a09e0e032e5f
   1
   1
   0
   /LM/W3SVC/760002457/ROOT/ReportingWebService-13-130401234012232311
   Full
   /ReportingWebService
   C:\Program Files\Update Services\WebServices\ReportingWebService\
   XYZ-SVR-101
   
   12936
   w3wp.exe
   NT-AUTORITÄT\Netzwerkdienst
   ConfigurationErrorsException
   Die Datei oder Assembly "Microsoft.UpdateServices.Reporting.Rollup_prior" oder eine Abhängigkeit davon wurde nicht gefunden. Die gefundene Manifestdefinition der Assembly stimmt nicht mit dem Assemblyverweis überein. (Ausnahme von HRESULT: 0x80131040) (C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Config\web.config line 111) bei System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) bei System.Web.Configuration.CompilationSection.LoadAllAssembliesFromAppDomainBinDirectory() bei System.Web.Configuration.AssemblyInfo.get_AssemblyInternal() bei System.Web.Compilation.BuildManager.GetReferencedAssemblies(CompilationSection compConfig) bei System.Web.Compilation.BuildManager.CallPreStartInitMethods(String preStartInitListPath, Boolean& isRefAssemblyLoaded) bei System.Web.Compilation.BuildManager.ExecutePreAppStart() bei System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager, IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory, HostingEnvironmentParameters hostingParameters, PolicyLevel policyLevel, Exception appDomainCreationException) Die Datei oder Assembly "Microsoft.UpdateServices.Reporting.Rollup_prior" oder eine Abhängigkeit davon wurde nicht gefunden. Die gefundene Manifestdefinition der Assembly stimmt nicht mit dem Assemblyverweis überein. (Ausnahme von HRESULT: 0x80131040) bei System.Reflection.RuntimeAssembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) bei System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, RuntimeAssembly reqAssembly, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) bei System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean forIntrospection) bei System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) bei System.Reflection.Assembly.Load(String assemblyString) bei System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective)  
   http://XYZ-svr-101:8530/reportingwebservice/reportingwebservice.asmx
   /reportingwebservice/reportingwebservice.asmx
   fe80::e1dd:c3f5:486c:cf90%12
   
   False
   
   NT-AUTORITÄT\Netzwerkdienst
   36
   NT-AUTORITÄT\Netzwerkdienst
   False
   bei System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) bei System.Web.Configuration.CompilationSection.LoadAllAssembliesFromAppDomainBinDirectory() bei System.Web.Configuration.AssemblyInfo.get_AssemblyInternal() bei System.Web.Compilation.BuildManager.GetReferencedAssemblies(CompilationSection compConfig) bei System.Web.Compilation.BuildManager.CallPreStartInitMethods(String preStartInitListPath, Boolean& isRefAssemblyLoaded) bei System.Web.Compilation.BuildManager.ExecutePreAppStart() bei System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager, IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory, HostingEnvironmentParameters hostingParameters, PolicyLevel policyLevel, Exception appDomainCreationException)
prior.png