Azure search: Multiple custom attributes of the same type found

Question

we are facing with a very strange problem with azure search which only happens on our live environment.

This is the code

var  aaa= new SearchServiceClient("name", new SearchCredentials("XXX"));

Literally one line of code, directly under Controller, the page breaks with following message:

[AmbiguousMatchException: Multiple custom attributes of the same type found.]
   System.Attribute.GetCustomAttribute(Assembly element, Type attributeType, Boolean inherit) +119
   Microsoft.Rest.ServiceClient`1.get_FrameworkVersion() +103
   Microsoft.Rest.ServiceClient`1.get_DefaultUserAgentInfoList() +120
   Microsoft.Rest.ServiceClient`1.SetUserAgent(String productName, String version) +50
   TMDApi.Controllers.HomeController.Fucker() in C:\PROJECTS\txfmd\TMDApi\Controllers\HomeController.cs:66
   lambda_method(Closure , ControllerBase , Object[] ) +87
   System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +209
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +35
   System.Web.Mvc.Async.AsyncControllerActionInvoker.<BeginInvokeSynchronousActionMethod>b__39(IAsyncResult asyncResult, ActionInvocation innerInvokeState) +40
   System.Web.Mvc.Async.WrappedAsyncResult`2.CallEndDelegate(IAsyncResult asyncResult) +71
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult) +43
   System.Web.Mvc.Async.AsyncInvocationWithFilters.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3d() +72
   System.Web.Mvc.Async.<>c__DisplayClass46.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3f() +385
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters(IAsyncResult asyncResult) +43
   System.Web.Mvc.Async.<>c__DisplayClass2b.<BeginInvokeAction>b__1c() +30
   System.Web.Mvc.Async.<>c__DisplayClass21.<BeginInvokeAction>b__1e(IAsyncResult asyncResult) +185
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +39
   System.Web.Mvc.Controller.<BeginExecuteCore>b__1d(IAsyncResult asyncResult, ExecuteCoreState innerState) +29
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +67
   System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +52
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +36
   System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +39
   System.Web.Mvc.MvcHandler.<BeginProcessRequest>b__5(IAsyncResult asyncResult, ProcessRequestState innerState) +43
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +67
   System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +39
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +656
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +143

We are using Azure.Search v4.0.0.0

Answer 1

This looks like a known compatibility issue with an older version of Application Insights. See this GitHub issue for details on how to resolve it.