I am getting the following error after having upgraded to 7.1.8 from 7.1.7. The site was working under 7.1.7 and only has Contour installed.

Server Error in '/' Application.


            
 Could not load file or assembly 
'System.Web.WebPages.Razor, Version=2.0.0.0, Culture=neutral, 
PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The module 
was expected to contain an assembly manifest. 

            

             Description: An unhandled exception occurred during 
the execution of the current web request. Please review the stack trace 
for more information about the error and where it originated in the 
code.

            



             Exception Details: System.BadImageFormatException: 
Could not load file or assembly 'System.Web.WebPages.Razor, 
Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or 
one of its dependencies. The module was expected to contain an assembly 
manifest.



            Source Error: 



            

               

                  

                      

An unhandled exception was generated during the execution of the current
 web request. Information regarding the origin and location of the 
exception can be identified using the exception stack trace below.

                  
               
            

            


            Stack Trace: 



            

               

                  

                      
[BadImageFormatException: Could not load file or assembly 'System.Web.WebPages.Razor, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The module was expected to contain an assembly manifest.]
   System.Web.Mvc.PreApplicationStartCode.Start() +0

[InvalidOperationException: The pre-application start initialization method Start on type System.Web.Mvc.PreApplicationStartCode threw an exception with the following error message: Could not load file or assembly 'System.Web.WebPages.Razor, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The module was expected to contain an assembly manifest..]
   System.Web.Compilation.BuildManager.InvokePreStartInitMethodsCore(ICollection`1 methods, Func`1 setHostingEnvironmentCultures) +12980619
   System.Web.Compilation.BuildManager.InvokePreStartInitMethods(ICollection`1 methods) +12980328
   System.Web.Compilation.BuildManager.CallPreStartInitMethods(String preStartInitListPath, Boolean& isRefAssemblyLoaded) +280
   System.Web.Compilation.BuildManager.ExecutePreAppStart() +172
   System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager, IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory, HostingEnvironmentParameters hostingParameters, PolicyLevel policyLevel, Exception appDomainCreationException) +1151

[HttpException (0x80004005): The pre-application start initialization method Start on type System.Web.Mvc.PreApplicationStartCode threw an exception with the following error message: Could not load file or assembly 'System.Web.WebPages.Razor, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The module was expected to contain an assembly manifest..]
   System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +12979668
   System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +159
   System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +12819261


                  







Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.34237
            

Any idea where I can look for a solution?

Thanks in advance