Failed to load file or assembly "AutoMapper" or one of its dependencies

Question

I have this problem when deploying, I really don't know how to solve it. Any idea?

Server Error in '/' Application. Could not load file or assembly 'AutoMapper' or one of its dependencies. This assembly is built by a runtime newer than the currently loaded runtime and cannot be loaded. 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 'AutoMapper' or one of its dependencies. This assembly is built by a runtime newer than the currently loaded runtime and cannot be loaded. 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 'AutoMapper' could not be loaded. === Pre-bind state information === LOG: User = IIS APPPOOL\DefaultAppPool LOG: DisplayName = AutoMapper (Partial) LOG: Appbase = file:///C:/inetpub/wwwroot/ LOG: Initial PrivatePath = C:\inetpub\wwwroot\bin Calling assembly : (Unknown). === LOG: This bind starts in default load context. LOG: Using application configuration file: C:\inetpub\wwwroot\web.config LOG: Using host configuration file:C:\Windows\Microsoft.NET\Framework64\v2.0.50727\Aspnet.config LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework64\v2.0.50727\config\machine.config. LOG: Policy not being applied to reference at this time (private, custom, partial, or location-based assembly bind). LOG: Attempting download of new URL file:///C:/Windows/Microsoft.NET/Framework64/v2.0.50727/Temporary ASP.NET Files/root/e22c2559/92c7e946/AutoMapper.DLL. LOG: Attempting download of new URL file:///C:/Windows/Microsoft.NET/Framework64/v2.0.50727/Temporary ASP.NET Files/root/e22c2559/92c7e946/AutoMapper/AutoMapper.DLL. LOG: Attempting download of new URL file:///C:/inetpub/wwwroot/bin/AutoMapper.DLL. ERR: Failed to complete setup of assembly (hr = 0x8013101b). Probing terminated. Stack Trace: [BadImageFormatException: Could not load file or assembly 'AutoMapper' or one of its dependencies. This assembly is built by a runtime newer than the currently loaded runtime and cannot be loaded.] System.Reflection.Assembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, Assembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection) +0 System.Reflection.Assembly.InternalLoad(AssemblyName assemblyRef, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) +416 System.Reflection.Assembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) +166 System.Reflection.Assembly.Load(String assemblyString) +35 System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) +190 [ConfigurationErrorsException: Could not load file or assembly 'AutoMapper' or one of its dependencies. This assembly is built by a runtime newer than the currently loaded runtime and cannot be loaded.] System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) [phone] System.Web.Configuration.CompilationSection.LoadAllAssembliesFromAppDomainBinDirectory() +388 System.Web.Configuration.CompilationSection.LoadAssembly(AssemblyInfo ai) +232 System.Web.Configuration.AssemblyInfo.get_AssemblyInternal() +48 System.Web.Compilation.BuildManager.GetReferencedAssemblies(CompilationSection compConfig) +210 System.Web.Compilation.BuildProvidersCompiler..ctor(VirtualPath configPath, Boolean supportLocalization, String outputAssemblyName) +76 System.Web.Compilation.ApplicationBuildProvider.GetGlobalAsaxBuildResult(Boolean isPrecompiledApp) +283 

System.Web.Compilation.BuildManager.CompileGlobalAsax () +50 System.Web.Compilation.BuildManager.EnsureTopLevelFilesCompiled () +676

  [HttpException (0x80004005): Could not load file or assembly 'AutoMapper' or one of its dependencies. This assembly is built by a runtime newer than the currently loaded runtime and cannot be loaded.] System.Web.Compilation.BuildManager.ReportTopLevelCompilationException() +76 System.Web.Compilation.BuildManager.EnsureTopLevelFilesCompiled() +1012 System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager, IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory, HostingEnvironmentParameters hostingParameters) +1025 [HttpException (0x80004005): Could not load file or assembly 'AutoMapper' or one of its dependencies. This assembly is built by a runtime newer than the currently loaded runtime and cannot be loaded.] System.Web.HttpRuntime.FirstRequestInit(HttpContext context) [phone] System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +88 System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +4348404 

Version Information: Microsoft.NET Framework Version: 2.0.50727.5446; ASP.NET Version: 2.0.50727.5420

Answer 1

The application pool is configured for .NET 2.0:

Version Information: Microsoft.NET Framework Version: 2.0.50727.5446; ASP.NET Version: 2.0.50727.5420

AutoMapper deployed build built for .NET 4.0:

"This assembly was built using a runtime that is newer than the currently loaded runtime and cannot be loaded."

This will not work. You can probably fix this by switching your application pool to .NET 4.0.

Answer 2

Try changing AppPool ... Right-click your application in IIS, Application Management => Advanced Settings => change pool. asp.net v4 pool worked for me ...

Answer 3

Check the link to the AutoMapper DLL - this may be incorrect. You may need to remove it and add it back.