无法加载文件或程序集'System.Web.Mvc'或其依赖项之一。 2个项目。 一次只能工作一个

Question

So i've got 2 website projects(among many other test/dll projects) in my solution.

Project A - CMS - Standard Web Project(with some Web API integration) Project B - Display Site - MVC 5.

I build Project A, and run it. It works, with no unexpected bugs. I then build Project B. Project B works, again with no unexpected bugs.

I go back to view something on Project A, and i get the following error at run-time.

Could not load file or assembly 'System.Web.Mvc' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

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.IO.FileLoadException: Could not load file or assembly 'System.Web.Mvc' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

[FileLoadException: Could not load file or assembly 'System.Web.Mvc' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)]
[FileLoadException: Could not load file or assembly 'System.Web.Mvc, Version=5.1.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)]
System.Reflection.RuntimeAssembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) +0
System.Reflection.RuntimeAssembly.nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) +34
System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, RuntimeAssembly reqAssembly, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) +152
System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean forIntrospection) +77
System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) +16
System.Reflection.Assembly.Load(String assemblyString) +28
System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) +38

[ConfigurationErrorsException: Could not load file or assembly 'System.Web.Mvc, Version=5.1.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)]
System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) +752
System.Web.Configuration.CompilationSection.LoadAllAssembliesFromAppDomainBinDirectory() +218
System.Web.Configuration.CompilationSection.LoadAssembly(AssemblyInfo ai) +130
System.Web.Compilation.BuildManager.GetReferencedAssemblies(CompilationSection compConfig) +170
System.Web.Compilation.BuildManager.GetPreStartInitMethodsFromReferencedAssemblies() +91
System.Web.Compilation.BuildManager.CallPreStartInitMethods(String preStartInitListPath, Boolean& isRefAssemblyLoaded) +285
System.Web.Compilation.BuildManager.ExecutePreAppStart() +153
System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager, IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory, HostingEnvironmentParameters hostingParameters, PolicyLevel policyLevel, Exception appDomainCreationException) +516

[HttpException (0x80004005): Could not load file or assembly 'System.Web.Mvc, Version=5.1.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)]
System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +9915300
System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +101
System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +254

I have to then build Project A to get it to load at run-time. it works, but then Project B has the same problem.

I've gone into the /bin/ folder of the Projects and observed something wierd. Say im looking at the /bin for Project A

If i build Project A, the System.Web.Mvc.dll file has a version of 5.1.20129.0 If i build Project B, the same DLL file changes its version back a step. To 5.0.11001.0

Using this information, i can understand why the error is firing, as the version it thinks it is is a higher version than the one that is there.

Also, it isn't getting synced with our Git Repository, as no other developers are getting the problem.

Anyone got any ideas as to how this began to happen? And possibly how i can fix it?

Ta

Answer 1

Right click on solutions and go to Start up project under Common properties, Chose multiple startup project, select both of your project. This will run both project and fix your problem.