Hi

We are moving several Umbraco sites from one server to another, however this one 6.1.1 site returns this error:

Could not load file or assembly 'System.Web.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.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.

Assembly Load Trace: The following information can be helpful to determine why the assembly 'System.Web.Razor, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' could not be loaded.


WRN: Assembly binding logging is turned OFF.
To enable assembly bind failure logging, set the registry value [HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1.
Note: There is some performance penalty associated with assembly bind failure logging.
To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fusion!EnableLog].

Stack Trace: 


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

[InvalidOperationException: The pre-application start initialization method Start on type Microsoft.Web.Helpers.PreApplicationStartCode threw an exception with the following error message: Could not load file or assembly 'System.Web.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) +874
   System.Web.Compilation.BuildManager.InvokePreStartInitMethods(ICollection`1 methods) +169
   System.Web.Compilation.BuildManager.CallPreStartInitMethods(String preStartInitListPath, Boolean& isRefAssemblyLoaded) +133
   System.Web.Compilation.BuildManager.ExecutePreAppStart() +176
   System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager, IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory, HostingEnvironmentParameters hostingParameters, PolicyLevel policyLevel, Exception appDomainCreationException) +734

[HttpException (0x80004005): The pre-application start initialization method Start on type Microsoft.Web.Helpers.PreApplicationStartCode threw an exception with the following error message: Could not load file or assembly 'System.Web.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) +579
   System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +112
   System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +712

Since there's no changes to anything, other than perhaps db connect string, we're wondering why this would happen.

Does anybody have any ideas, clues or anything ?

Kind regards, Bruno