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System.BadImageFormatException: Bad binary signature. in Azure App Service

I have made an ASP.NET Core (.Net 5) Web API which works perfectly fine on my local machine. And actually all contorllers except one work fine too. When I make a Post Request to my DataStoreController I get the following exception:
System.BadImageFormatException: Bad binary signature. (0x80131192)
at
System.Runtime.CompilerServices.RuntimeHelpers._CompileMethod(RuntimeMethodHandleInternal
method) at System.Reflection.Emit.DynamicMethod.CreateDelegate(Type
delegateType, Object target) at
System.Linq.Expressions.Compiler.LambdaCompiler.Compile(LambdaExpression
lambda) at System.Linq.Expressions.Expression`1.Compile() at
Microsoft.Extensions.Internal.ObjectMethodExecutor.GetExecutor(MethodInfo
methodInfo, TypeInfo targetTypeInfo) at
Microsoft.Extensions.Internal.ObjectMethodExecutor..ctor(MethodInfo
methodInfo, TypeInfo targetTypeInfo, Object[] parameterDefaultValues)
at
Microsoft.Extensions.Internal.ObjectMethodExecutor.Create(MethodInfo
methodInfo, TypeInfo targetTypeInfo, Object[] parameterDefaultValues)
at
Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvokerCache.GetCachedResult(ControllerContext
controllerContext) at
Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvokerProvider.OnProvidersExecuting(ActionInvokerProviderContext
context) at
Microsoft.AspNetCore.Mvc.Infrastructure.ActionInvokerFactory.CreateInvoker(ActionContext
actionContext) at
Microsoft.AspNetCore.Mvc.Routing.ActionEndpointFactory.<>c__DisplayClass7_0.b__0(HttpContext
context) at
Microsoft.AspNetCore.Routing.EndpointMiddleware.Invoke(HttpContext
httpContext)
--- End of stack trace from previous location --- at Swashbuckle.AspNetCore.SwaggerUI.SwaggerUIMiddleware.Invoke(HttpContext
httpContext) at
Swashbuckle.AspNetCore.Swagger.SwaggerMiddleware.Invoke(HttpContext
httpContext, ISwaggerProvider swaggerProvider) at
Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext
context)
I have tried what would happen if I made the Method inside the Controller empty and just return null - but still the same error. The only differnce package-wise to the other controllers is that the DataStoreController uses the Stackexchange.Redis NuGet Package.
My gut feeling tells me that this is a weird Azure Bug, but I would love to get some opinions/advices/answers from you.

Okay okay. I have kind of found a solution.
I stopped and started the App Service and now everything works. This actually might be a weird Azure Issue.

Setting HttpRuntime.WebObjectActivator makes HttpApplication.InitModulesCommon throw a NullReferenceException

Setting HttpRuntime.WebObjectActivator makes HttpApplication.InitModulesCommon throw a NullReferenceException.
I'm setting it in my Application_Start and setting it back to null makes the error go away so its consistent.
The stacktrace is as follows
[NullReferenceException: Object reference not set to an instance of an object.]
System.Web.HttpApplication.InitModulesCommon() +166
System.Web.HttpApplication.InitInternal(HttpContext context, HttpApplicationState state, MethodInfo[] handlers) +792
System.Web.HttpApplicationFactory.GetNormalApplicationInstance(HttpContext context) +153
System.Web.HttpApplicationFactory.GetApplicationInstance(HttpContext context) +107
System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +327
My best guess is that its this line which is failing https://referencesource.microsoft.com/#system.web/HttpApplication.cs,2337 due to all modules being resolved by the WebObjectActivator and therefor returning null if they arent registered as seen here https://referencesource.microsoft.com/#system.web/ModulesEntry.cs,62 and here https://referencesource.microsoft.com/#system.web/HttpRuntime.cs,3388
By is that really the case... ? Is it really the responsibility of the activator to instantiate objects which isn't registered as well?

Reading the answer to this question unfortunately confirms that whoever cooked up HttpRuntime.WebObjectActivator wasn't thinking it through
Wiring up Simple Injector in WebForms in .NET 4.7.2

ResolutionFailedException with Unity

I'm using Patterns and Practices' Unity to inject dependencies into my objects and have hit a weird (to me, anyway) issue. Here's my class definitions:
public class ImageManager : IImageManager
{
IImageFileManager fileManager;
public ImageManager(IImageFileManager fileMgr)
{
this.fileManager = fileMgr;
}
}
public class ImageFileManager : IImageFileManager
{
public ImageFileManager(string folder)
{
FileFolder = folder;
}
}
And here's the code to register my classes
container.RegisterInstance<MainWindowViewModel>(new MainWindowViewModel())
.RegisterType<IPieceImageManager, PieceImageManager>(
new InjectionConstructor(typeof(string)))
.RegisterType<IImageFileManager, ImageFileManager>()
.RegisterType<IImageManager, ImageManager>(
new InjectionConstructor(typeof(IImageFileManager)));
I originally resolved this in the code behind (I know, it defeats the purpose. Bear with me.) of the XAML file like this
IImageManager imageManager = MvvmViewModelLocator.Container.Resolve<IImageManager>(
new ParameterOverride("folder", "/images"));
And it worked. But I created a view model for my main view and when I copied the same line into it, I get an exception. Here are the two most inner exceptions:
InnerException: Microsoft.Practices.Unity.ResolutionFailedException
HResult=-2146233088
Message=Resolution of the dependency failed, type = "SwapPuzzleApp.Model.IImageManager", name = "(none)".
Exception occurred while: while resolving.
Exception is: InvalidOperationException - The type IImageManager does not have an accessible constructor.
At the time of the exception, the container was:
Resolving SwapPuzzleApp.Model.IImageManager,(none)
Source=Microsoft.Practices.Unity
TypeRequested=IImageManager
StackTrace:
at Microsoft.Practices.Unity.UnityContainer.DoBuildUp(Type t, Object existing, String name, IEnumerable`1 resolverOverrides)
at Microsoft.Practices.Unity.UnityContainer.DoBuildUp(Type t, String name, IEnumerable`1 resolverOverrides)
at Microsoft.Practices.Unity.UnityContainer.Resolve(Type t, String name, ResolverOverride[] resolverOverrides)
at Microsoft.Practices.Unity.UnityContainerExtensions.Resolve[T](IUnityContainer container, ResolverOverride[] overrides)
at SwapPuzzleApp.ViewModel.MainWindowViewModel..ctor() in c:\Users\Carole\Documents\Visual Studio 2012\Projects\SwapPuzzle\SwapPuzzle\ViewModel\MainWindowViewModel.cs:line 17
at SwapPuzzleApp.ViewModel.MvvmViewModelLocator..cctor() in c:\Users\Carole\Documents\Visual Studio 2012\Projects\SwapPuzzle\SwapPuzzle\ViewModel\MvvmViewModelLocator.cs:line 51
InnerException: System.InvalidOperationException
HResult=-2146233079
Message=The type IImageManager does not have an accessible constructor.
Source=Microsoft.Practices.Unity
StackTrace:
StackTrace:
at Microsoft.Practices.ObjectBuilder2.DynamicMethodConstructorStrategy.ThrowForNullExistingObject(IBuilderContext context)
at lambda_method(Closure , IBuilderContext )
at Microsoft.Practices.ObjectBuilder2.DynamicBuildPlanGenerationContext.<>c__DisplayClass1.<GetBuildMethod>b__0(IBuilderContext context)
at Microsoft.Practices.ObjectBuilder2.DynamicMethodBuildPlan.BuildUp(IBuilderContext context)
at Microsoft.Practices.ObjectBuilder2.BuildPlanStrategy.PreBuildUp(IBuilderContext context)
at Microsoft.Practices.ObjectBuilder2.StrategyChain.ExecuteBuildUp(IBuilderContext context)
at Microsoft.Practices.Unity.UnityContainer.DoBuildUp(Type t, Object existing, String name, IEnumerable`1 resolverOverrides)
InnerException:
I'm not sure what the problem is, as ImageManager clearly has a public constructor. I thought it might be due to an invalid path, but if I concretely instantiate the object, everything works.
// this line has no problems
IImageManager imageManager = new ImageManager(new ImageFileManager("/images"));
I also wondered if I needed to pass in new InjectionConstructor(typeof(string)) when I register IImageManager, but it doesn't seem to help and why would it be needed now and not before? So I'm stumped. This is my first attempt at using Dependency Injection, so it's probably something basic. I'm just not seeing what, though.

Look very closely at the error message. Notice this part:
Message=The type IImageManager does not have an accessible constructor.
Notice the type name is IImageManager, not ImageManager. Somewhere along the line you lost your type mapping.
Your registration of FileImageManager has a problem as well, since you don't specify the folder parameter in the registration, so Unity has no idea what string to pass.

I was using the examples in this article as my guide. Either the examples in there are way too advanced for an introduction, or there's misinformation in that topic.
After consulting other sources (mainly PluarlSight), I came up with a much simpler and more logical solution.
container.RegisterInstance<TimerViewModel>(new TimerViewModel());
container.RegisterType<IPieceImageManager, PieceImageManager>();
container.RegisterType<IImageFileManager, ImageFileManager>
(new InjectionConstructor("/images"));
container.RegisterType<IImageManager, ImageManager>();

I ran into a similar issue with this error tied directly to a Mock (using automoq) that I was doing for an operation. In this case it turned out that because there were a number of member methods that get called with the object being mocked, that I had to define all of those in the automoq chain to get it to resolve properly
I realize this is an example in instance code, but it could occur in Moqs also. So if you read this and are wondering about an example related to Moqs, look into that first.

Linq- Random Item with same key has already been added Error

I am getting error "An item with the same key has already been added." I get this error randomly when many user try to access the same page on site in production at the same time.
In the code docid is passed and relevant help is displayed to user. As each user is viewing the same page so same ID is passed for all users. There is no insert operation in this call
Stack trace and souce code of mentioned line is given as follows
public string DocDescription(int docid)
{
DocumentRepository _Documentrepository = new DocumentRepository();
return _Documentrepository.GetDocDescription(docid);
}
}
public string GetDocDescription(int DocID)
{
if (DocID != 0)
return db.sysDocuments.SingleOrDefault(p => p.DocumentID == DocID).Description==null?"No Description Available":db.sysDocuments.SingleOrDefault(p => p.DocumentID == DocID).Description;
else
return "No Description Available";
}
Stack Trace excerpt:
System.Web.HttpException (0x80004005): Error executing child request for handler 'System.Web.Mvc.HttpHandlerUtil+ServerExecuteHttpHandlerWrapper'. ---> System.Web.HttpUnhandledException (0x80004005): Exception of type 'System.Web.HttpUnhandledException' was thrown. ---> System.Web.HttpException (0x80004005): Error executing child request for handler 'System.Web.Mvc.HttpHandlerUtil+ServerExecuteHttpHandlerAsyncWrapper'. ---> System.ArgumentException: An item with the same key has already been added.
at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)
at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
at System.Data.Linq.DataContext.GetTable(MetaTable metaTable)
at System.Data.Linq.DataContext.GetTable[TEntity]()
at UserManagement.Models.DocumentRepository.GetDocDescription(Int32 DocID) in D:\Myproj\UserManagement\UserManagement\Models\DocumnetRepository.cs:line 109
at lambda_method(Closure , ControllerBase , Object[] )
at System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters)
at System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters)
at Castle.Proxies.ControllerActionInvokerProxy.InvokeActionMethod_callback(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters)
at Castle.Proxies.Invocations.ControllerActionInvoker_InvokeActionMethod.InvokeMethodOnTarget()
at Castle.DynamicProxy.AbstractInvocation.Proceed()
at Glimpse.Net.Interceptor.InvokeActionMethodInterceptor.Intercept(IInvocation invocation)
at Castle.DynamicProxy.AbstractInvocation.Proceed()

From your code and comments, I get that you store db context in a static variable. This is generally a bad idea when working with entities.
DbContext is not thread safe. So, multiple users working with your site will cause such errors in context.
The general suggestion for working with context is to prefer short lived context. So just create a new instance, when you need it, and then forget it. For the web sites, it is quite common to use inversion of control container like Unity, Castle.Winsdor etc, and configure it to return one instance per web request for your DbContext. This will give you enough performance, so all entities needed for the current request are cached, and will not cause threading issues at the same time.

See comment too, static members are application scoped variables thus they're sharing the same dictionary which can throw errors like this if multiple requests add the same key.

How can I prevent EF "The context cannot be used while the model is being created" errors?

Looking at my Elmah error logs, I am seeing a few InvalidOperationExceptions from Entity Framework that deal with:
The context cannot be used while the model is being created.
This is with the latest EF CodeFirst library from Nuget. The only information I have been able to find on the net is that it is being caused by having data contexts as singletons, which is most certainly not my case. In my Windsor installer, my EF unit of work structure is being registered with:
container.Register(Component.For<IUnitOfWork>()
.ImplementedBy<EFUnitOfWork>()
.LifeStyle
.PerWebRequest);
I am able to recreate the error by hitting F5 in VS to start a debugging sessions, and while IIS is spinning up load up a second webpage to the debug session.
I suspect it is because the user is trying to access the system while Asp.net has unloaded due to the lack of activity, which makes sense as my product is currently in a very very small beta test. However, since real people are using the website with live data, I need as little errors occurring as possible.
Does anyone have any idea how to prevent this from occurring?
Edit: I updated my windsor controller to now contain the following code:
container.Register(Component.For<IUnitOfWork>().ImplementedBy<EFUnitOfWork>().LifeStyle.PerWebRequest);
using (var context = new MyJobLeadsDbContext())
{
context.Set<UnitTestEntity>().Any();
}
However, when I attempt to perform a 2nd web request while IIS is loading the application, the previous error still occurs
Edit 2: As requested, here is the stack
at System.Data.Entity.Internal.LazyInternalContext.InitializeContext()
at System.Data.Entity.Internal.InternalContext.Initialize()
at System.Data.Entity.Internal.InternalContext.GetEntitySetAndBaseTypeForType(Type entityType)
at System.Data.Entity.Internal.Linq.InternalSet`1.Initialize()
at System.Data.Entity.Internal.Linq.InternalSet`1.get_InternalContext()
at System.Data.Entity.Infrastructure.DbQuery`1.System.Linq.IQueryable.get_Provider()
at System.Linq.Queryable.Where[TSource](IQueryable`1 source, Expression`1 predicate)
at MyApp.DomainModel.Queries.Users.UserByEmailQuery.Execute() in C:\Users\KallDrexx\Documents\Projects\MyApp\MyApp.DomainModel\Queries\Users\UserByEmailQuery.cs:line 44
at MyApp.Infrastructure.MyAppMembershipProvider.GetUser(String email, Boolean userIsOnline) in C:\Users\KallDrexx\Documents\Projects\MyApp\MyApp\Infrastructure\MyAppMembershipProvider.cs:line 102
at System.Web.Security.Membership.GetUser(String username, Boolean userIsOnline)
at System.Web.Security.Membership.GetUser()
at MyApp.MyAppBaseController.Initialize(RequestContext requestContext) in C:\Users\KallDrexx\Documents\Projects\MyApp\MyApp\MyAppBaseController.cs:line 23
at System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext)
at System.Web.Mvc.ControllerBase.System.Web.Mvc.IController.Execute(RequestContext requestContext)
at System.Web.Mvc.MvcHandler.<>c__DisplayClass6.<>c__DisplayClassb.<BeginProcessRequest>b__5()
at System.Web.Mvc.Async.AsyncResultWrapper.<>c__DisplayClass1.<MakeVoidDelegate>b__0()
at System.Web.Mvc.Async.AsyncResultWrapper.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`1.End()
at System.Web.Mvc.MvcHandler.<>c__DisplayClasse.<EndProcessRequest>b__d()
at System.Web.Mvc.SecurityUtil.<GetCallInAppTrustThunk>b__0(Action f)
at System.Web.Mvc.SecurityUtil.ProcessInApplicationTrust(Action action)
at System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult)
at System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

I finally figured out the true cause of this, at least for me.
The issue was that I was retrieving a DbContext from Windsor in my custom Asp.Net Membership provider. This caused an issue because the membership provider has a lifespan of the whole application, while all other retrieval calls for the db context were new db contexts for the specific web requests. This meant that two database contexts were "spinning up" at the same time and thus this error was thrown.
This also caused a lot of hard to debug entity caching issues as well, so anyone who uses EF in their membership provider needs to be real careful about their context lifetime.
Edit: In response to DotNetWise, I solved this by forcing my custom membership provider to always use an EF connection from Windsor by storing the Windsor connection factory in my constructor, then always retrieving my EF data context from the factory at that point.
For example:
public class CustomMembershipProvider : MembershipProvider
{
private IServiceFactory _serviceFactory;
public CustomMembershipProvider() : this(null) { }
public CustomMembershipProvider(IServiceFactory factory)
{
// IF no factory was provided, we need to get one from the bootstrapper
if (factory == null)
_serviceFactory = new WindsorServiceFactory(Bootstrapper.WindsorContainer);
else
_serviceFactory = factory;
}
public override string ResetPassword(string email, string answer)
{
var unitOfWork = GetUnitOfWork();
return new ResetUserPasswordCommand(unitOfWork).WithUserEmail(email).Execute();
}
private IUnitOfWork GetUnitOfWork()
{
return _serviceFactory.GetService<IUnitOfWork>();
}
}
The idea being that any action the membership provider performs gets the UnitOfWork class from Windsor, and uses that to perform the action (in this case my UnitOfWork class is a repository holder to wrap up my EF data context)

I ran into the same issue in a multithreaded WPF app.
My workaround was to force DbContext initialization from the Windsor installer:
container.Register(Component.For(TheDbContext.Blah.Blah));
using (var context = new TheDbContext())
context.Set<SomeRandomEntity>().Any();
I might add in my opinion this qualifies as a bug in EF: they should have used thread-safe (with locks, or whatever) code for DbContext initialization.
Of course, a better solution is what NHibernate does: the SessionFactory is an explicitly created, separate object from the Session.

When i encountered this issue, i found it was a dbconnection gone wrong.
I corrected my EntityFramework dbconnection string and all was fine