System.NullReferenceException at Microsoft.AspNetCore.Http.DefaultHttpRequest.get_HasFormContentType()

[rexpan]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

Sometime I got the error System.NullReferenceException at Microsoft.AspNetCore.Http.DefaultHttpRequest.get_HasFormContentType() for several GET API.

Expected Behavior

No response

Steps To Reproduce

No response

Exceptions (if any)

Error: Object reference not set to an instance of an object.System.NullReferenceException: Object reference not set to an instance of an object.
at Microsoft.AspNetCore.Http.DefaultHttpRequest.get_HasFormContentType()
at Microsoft.AspNetCore.Mvc.ModelBinding.FormValueProviderFactory.CreateValueProviderAsync(ValueProviderFactoryContext context)
at Microsoft.AspNetCore.Mvc.ModelBinding.CompositeValueProvider.CreateAsync(ActionContext actionContext, IList`1 factories)
at Microsoft.AspNetCore.Mvc.ModelBinding.CompositeValueProvider.TryCreateAsync(ActionContext actionContext, IList`1 factories)
at Microsoft.AspNetCore.Mvc.Controllers.ControllerBinderDelegateProvider.<>c__DisplayClass0_0.<<CreateBinderDelegate>g__Bind|0>d.MoveNext()

.NET Version

6.0.202

Anything else?

No response

[davidfowl]

That's really strange. Are you running on IIS or Kestrel? Do you have a repro? Is that the entire call stack?

Hi @rexpan. We have added the "Needs: Author Feedback" label to this issue, which indicates that we have an open question for you before we can take further action. This issue will be closed automatically in 7 days if we do not hear back from you by then - please feel free to re-open it if you come back to this issue after that time.

[arisewanggithub]

Our service has the same issue. This happens for a very small portion of the requests.

[davidfowl]

Are you using application insights?

[arisewanggithub]

yes.

[arisewanggithub]

We use Kestrel. No idea how to repro it. This is just observed from the logs from app insights from our production traffic.
The exception is thrown inside the await _next(context) in the last middleware we have. So, it shouldn't be caused by our own code.
public async Task Invoke(HttpContext context)
{
...
await _next(context);
}

[arisewanggithub]

This is our stack trace. To remove project related code, I renamed our last middleware to MyCustomMiddleware and removed the stacks before it. But it should be enough to show where the issue is:
System.NullReferenceException:
at Microsoft.AspNetCore.Http.DefaultHttpRequest.get_HasFormContentType (Microsoft.AspNetCore.Http, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60)
at Microsoft.AspNetCore.Mvc.ModelBinding.FormValueProviderFactory.CreateValueProviderAsync (Microsoft.AspNetCore.Mvc.Core, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60)
at Microsoft.AspNetCore.Mvc.ModelBinding.CompositeValueProvider+d__3.MoveNext (Microsoft.AspNetCore.Mvc.Core, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Microsoft.AspNetCore.Mvc.ModelBinding.CompositeValueProvider+d__4.MoveNext (Microsoft.AspNetCore.Mvc.Core, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Microsoft.AspNetCore.Mvc.Controllers.ControllerBinderDelegateProvider+<>c__DisplayClass0_0+<g__Bind|0>d.MoveNext (Microsoft.AspNetCore.Mvc.Core, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker+<g__Awaited|13_0>d.MoveNext (Microsoft.AspNetCore.Mvc.Core, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker+<g__Awaited|20_0>d.MoveNext (Microsoft.AspNetCore.Mvc.Core, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker+<g__Logged|17_1>d.MoveNext (Microsoft.AspNetCore.Mvc.Core, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker+<g__Logged|17_1>d.MoveNext (Microsoft.AspNetCore.Mvc.Core, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Microsoft.AspNetCore.Routing.EndpointMiddleware+<g__AwaitRequestTask|6_0>d.MoveNext (Microsoft.AspNetCore.Routing, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at MyCustomMiddleware

[davidfowl]

Are you using SQL server anywhere?

[arisewanggithub]

Nope

[davidfowl]

Here's an example of an issue we just fixed in SqlClient that appeared as a null reference exception in ASP.NET Core when used with app insights #41924.

@okolvik-avento did a really helpful investigation by getting us a crash dump we could use to quickly identify the problem. He's written a helpful guide that could assist you in collecting a dump here https://okolvik-avento.github.io/pages/2022-06-05-creating-iis-userdumps.

It would also help if you could identify which pieces of the code are using TelemetryClient